Pluripotent stem cells (PSCs) are undifferentiated cells characterized by their ability to self-renew indefinitely and differentiate into any cell type originating from ectoderm, mesoderm, and endoderm¹.

Pluripotent stem cells can generate any cell or tissue of the body. PSCs originate from either embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs). ESCs are obtained from the inner cell mass of blastocysts, whereas reprogramming of somatic cells generates iPSCs.

With their immense potential, pluripotent stem cells are a beacon of hope for regenerative medicine. They provide a readily available and replenishable source of stem cells for research related to human development, disease onset, and potential therapeutics. Several clinical trials are currently underway to test cells and tissues derived from pluripotent stem cells as therapies for a wide range of ailments such as diabetes, Parkinson’s disease, spinal cord injury, blindness, and thrombocytopenia^2,3,4,5.

Characteristics and mechanisms of pluripotency

The hallmark of pluripotent stem cells is their ability to differentiate and self-renew. Pluripotency is the ability of a stem cell to differentiate into any cell type.

Self-renewal

Self-renewal is one of the distinguishing features of pluripotent stem cells. This feature enables PSCs to divide indefinitely while preserving their undifferentiated state.

Self-renewal is essential for maintaining a consistent supply of pluripotent stem cells, which is vital for maintaining long-term cultures and advancing research in disease regulation and therapeutic development. Self-renewal is governed by tightly regulated intrinsic genetic programs and extrinsic signaling pathways that uphold genomic stability and prevent spontaneous differentiation.

However, when exposed to specific external signals, PSCs lose their stem cell-like properties and initiate the process of differentiation⁶. For example, bone morphogenetic proteins and transforming growth factor-beta (TGF-β) family members promote mesodermal and endodermal differentiation by activating Smad signaling pathways⁷.

Differentiation potential

By using simple biochemical cues or activating specific signaling pathways, PSCs can be guided to form distinct cell types in vitro. This capacity to generate specialized cells makes PSCs invaluable in regenerative medicine, where they hold the potential for treating diseased or damaged tissues through cell replacement therapies. In Parkinson’s disease research, PSC-derived dopaminergic neurons have been transplanted into patients to restore dopamine production and alleviate motor symptoms. Research has shown promising results in preclinical and early clinical trials⁸.

Key genes and signaling pathways involved in maintaining pluripotency

Pluripotency is maintained through the coordinated activation of transcription factors and signaling pathways that regulate self-renewal and suppress differentiation. Core transcription factors such as Octamer-binding transcription factor 4 (OCT4), SRY (sex-determining region Y)-Box 2 (SOX2), and NANOG, establish and sustain the undifferentiated state by orchestrating gene expression networks essential for pluripotency⁹.

Additionally, extrinsic signaling pathways contribute to this regulatory framework. Fibroblast growth factor signaling supports self-renewal and proliferation¹⁰, while the TGF-β/activin/nodal pathway modulates the balance between pluripotency and differentiation¹¹. Wnt signaling further influences lineage specification, ensuring controlled fate determination^12,13. These factors operate synergistically, preserving pluripotency until differentiation signals initiate lineage commitment.

Role of transcription factors in the pluripotent state

The transcription factors OCT4, SOX2, and NANOG play vital roles in the establishment and long-term maintenance of stem cell pluripotency. OCT4 and SOX2 interact to form a regulatory complex that not only activates a wide array of genes essential for sustaining the pluripotent state but also simultaneously represses the expression of genes that drive cellular differentiation¹⁴. NANOG further enhances and stabilizes this core regulatory network by promoting continuous self-renewal and exerting additional inhibitory control over differentiation pathways¹⁵.

The dynamic and synergistic interplay among OCT4, SOX2, and NANOG gives rise to a robust and resilient transcriptional circuit that safeguards the unique identity, plasticity, and functional integrity of pluripotent stem cells⁹. Any disruption, imbalance, or alteration in the expression or activity of these key factors can compromise this regulatory equilibrium, thereby initiating the process of differentiation and leading to the loss of pluripotency¹⁶.

Types of pluripotent stem cells

Pluripotent stem cells can be classified into two distinct categories: embryonic stem cells and induced pluripotent stem cells. Each class exhibits unique properties that influence its applicability in research and therapeutic contexts.

Pluripotent stem cells are important in scientific research. ESCs represent the gold standard for studying early human development and differentiation. iPSCs exhibit characteristics similar to ESCs while circumventing the ethical concerns associated with embryo-derived cells. Both ESCs and iPSCs can be maintained in vitro in a pluripotent state.

Embryonic stem cells

ESCs are derived from the inner cell mass of blastocyst-stage embryos. Their naive pluripotent state offers the widest potential for differentiation, expanding their utility in scientific research. For example, in a study on Alzheimer’s disease rats, researchers found that ESCs improved spatial learning and memory by generating gamma-aminobutyric acid (GABA) neurons and cholinergic neurons from basal forebrain cells, thereby enhancing cognitive functions¹⁷.

However, extracting ESCs requires the destruction of embryos, raising significant ethical concerns¹⁸. These ethical issues have driven the pursuit of alternative pluripotent stem cell sources, such as iPSCs, which do not use embryos.

Induced pluripotent stem cells

iPSCs are pluripotent cells generated by reprogramming adult somatic cells through the introduction of specific transcription factors such as OCT4 and SOX2¹⁹. The reprogramming process silences somatic cell genes while activating pluripotency-associated genes, effectively transforming adult cells into a pluripotent state. iPSCs closely resemble ESCs in their ability to differentiate into any cell type, but they avoid the ethical concerns associated with embryo use.

iPSCs can be derived from a patient’s cells, reducing the risk of immune rejection, making them valuable for personalized medicine. For example, organoids derived from iPSCs have been successfully utilized for basic research, precision medicine, disease modeling, and drug screening and discovery²⁰.

Induced pluripotent stem cells vs. embryonic stem cells

Although iPSCs and ESCs share similar capabilities for pluripotency, differentiation, and self-renewal, they differ significantly in origin, epigenetic memory, and genetic stability²¹.

Key similarities between ESCs and iPSCs

iPSCs and ESCs can be maintained in a pluripotent state, generating an infinite number of differentiated cells. Additionally, both ESCs and iPSCs exhibit similarities in terms of gene expression, chromatin modification, and global epigenetic profiles^22,23.

In vitro, under appropriate culture conditions involving growth factors, ESCs and iPSCs can self-renew indefinitely. This highlights the usefulness of PSCs in research and medicine.

Differences between ESCs and iPSCs

Origin: iPSCs are derived from a range of adult somatic cell types through various reprogramming procedures, whereas ESCs are isolated from the inner cell mass of the blastocyst.

Epigenetic memory: ESCs retain the embryo’s native epigenetic markers, whereas iPSCs may preserve residual epigenetic and transcriptional signatures, such as DNA methylation patterns, from their tissue of origin, potentially influencing their differentiation behavior^24,25.

Genetic stability: The reprogramming process and prolonged in vitro culture may compromise the genetic stability of iPSCs, potentially affecting their suitability for therapeutic applications²¹.

Comparative analysis between ESCs and iPSCs

Functional equivalence: While iPSCs and ESCs are functionally comparable in many respects, iPSCs offer distinct advantages in specific applications. iPSCs can potentially overcome the issue of immune rejection in regenerative medicine. In contrast, ESCs often demonstrate higher intrinsic differentiation efficiency due to their naive pluripotent state.

Differentiation efficiency: Studies have shown that well-characterized iPSC lines can exhibit functional properties similar to ESCs across various differentiation lineages^26,27,28. However, subtle differences in gene expression profiles and differentiation kinetics highlight the need for rigorous characterization of individual iPSC lines. The efficiency of directed differentiation protocols can vary between iPSC lines and compared to ESCs, partly due to epigenetic memory retained from their tissue of origin. Researchers continue to refine differentiation methods to enhance the robustness and efficiency of cell types derived from both iPSCs and ESCs.

Immunogenicity: In terms of immunogenicity, iPSCs provide a significant advantage by enabling autologous transplantation, theoretically eliminating the risk of immune rejection associated with allogeneic ESC-derived therapies. Nevertheless, the reprogramming process may introduce neoantigens²⁹, which could provoke immune responses even in autologous settings. Ongoing research aims to better understand and mitigate the immunogenic potential of iPSC-based therapies to fully realize their clinical promise.

Applications of pluripotent stem cells

Pluripotent stem cells have numerous applications in research, drug discovery, and therapeutics. PSCs provide a model system for investigating human development and the pathogenesis of diseases under in vitro conditions.

Regenerative medicine and tissue engineering

Pluripotent stem cells are central to advancing regenerative medicine and tissue engineering, offering the potential to generate replacement tissues and organs for conditions such as Parkinson’s disease, heart disease, and diabetes. Ongoing research focuses on differentiating PSCs into specialized cell types such as neurons, cardiomyocytes, and insulin-producing beta cells, for therapeutic applications. For example, pluripotent stem cell-derived Schwann cell precursors have been explored as a potential therapy for promoting myelin repair³⁰.

Tissue engineering, a key branch of regenerative medicine, focuses on creating three-dimensional tissues or organs by combining stem cells, scaffolds, and growth factors. These approaches are used to develop skin grafts for burn victims, cartilage for joint repair, and more complex constructs such as liver tissues and heart muscle patches^31,32,33,34. Both embryonic stem cells and induced pluripotent stem cells are being studied for these applications.

Disease modeling

Pluripotent stem cells, particularly iPSCs, serve as a powerful tool for disease modeling and personalized medicine. Generated iPSCs can be used to create disease-specific cell lines to replicate symptoms of different diseases. iPSC-derived models offer a valuable tool for investigating the cellular and molecular mechanisms that drive disease onset and progression. These systems can be leveraged to screen large libraries of compounds for potential therapeutic agents and to develop personalized therapies tailored to the genetic profiles of individual patients^35,36,37,38. iPSC-based models have been successfully established for a wide range of diseases, including neurodegenerative disorders, cardiovascular diseases, and various genetic conditions.

Current research and advancements of pluripotent stem cells

PSCs in personalized medicine can replace damaged or diseased cells³⁹. PSCs also offer promising avenues in gene therapy by enabling the correction or replacement of faulty genes through stem cell-based technologies.

Currently, research focuses on using PSC-derived cells and organoids for high-throughput drug screening and toxicology studies, offering human-relevant systems that may reduce reliance on animal models⁴⁰. Advanced stem cell therapies or tissue engineering techniques could revolutionize the repair or replacement of damaged tissues and organs, such as the heart, liver, and kidneys. Furthermore, PSCs provide hope for developing novel treatments for currently incurable neurological disorders such as Parkinson’s disease and multiple sclerosis⁴¹, potentially transforming the future of medicine.

Pluripotent stem cells provide hope for generating novel treatments for currently incurable neurological disorders such as Parkinson’s disease and multiple sclerosis. These cells have the potential to revolutionize the medical landscape in the future.

Breakthrough studies involving pluripotent stem cells

Recent research has highlighted the therapeutic potential of PSCs in various preclinical and clinical settings.

Clinical trials are underway to evaluate the safety and efficacy of ESC-derived and iPSC-derived cell therapies for conditions such as macular degeneration, spinal cord injury, and heart failure^42,43. For example, iPSCs show promise for treating age-related macular degeneration by replacing damaged retinal pigment epithelium (RPE) cells⁴⁴.

Significant progress has been made in the directed differentiation of PSCs into specific cell types with high purity and functionality, improving the feasibility of cell-based therapies⁴⁵. For example, patients are treated for diabetes using pancreatic islet replacement therapy, wherein differentiated stem cells are transplanted to generate insulin-producing cells⁴⁶.

Researchers are developing sophisticated bioreactors and three-dimensional culture systems to scale up the production of PSC-derived cells and tissues for clinical applications. Recent advances have focused on three-dimensional stem cell culture systems, highlighting their potential to better simulate the in vivo microenvironment and thereby enhance the proliferation and differentiation of stem cells for therapeutic applications.

iPSC-based studies have provided vital insights into the molecular mechanisms underlying myelodysplastic syndromes by generating patient-specific models that recapitulate disease phenotypes. These models have uncovered dysregulated RNA splicing pathways and specific splicing factor mutations, which contribute to aberrant hematopoietic differentiation, impaired cellular function, and disease progression in MDS^48,49.

Development of CRISPR/Cas9 gene editing technology

A major leap forward has been the integration of precise gene editing technologies, particularly CRISPR/Cas9, into PSC research⁵⁰.

CRISPR/Cas9 enables targeted genome modifications with unprecedented efficiency and accuracy. This technology is being used to correct disease-causing mutations in iPSCs, paving the way for autologous, gene-corrected cell therapies. One study employed CRISPR/Cas9 to correct the sickle hemoglobin mutation in iPSCs derived from sickle cell disease patients⁵¹. After gene correction, the iPSCs were differentiated into hematopoietic stem cells, offering potential therapeutic strategies for sickle cell disease through autologous cell transplantation.

Isogenic cell lines are being generated using CRISPR/Cas9 technology to study the functional impact of specific genetic alterations, to engineer PSCs for enhanced differentiation efficiency, and to investigate gene functions vital for pluripotency, self-renewal, and lineage commitment⁵².

Challenges and ethical considerations

Although pluripotent stem cell therapies hold significant promise, they present considerable challenges related to safety, potency, immunogenicity, genetic stability, cell reproducibility, and scalability.

Determining the full sequence of lineage stages necessary for differentiating pluripotent stem cells into the appropriate cell type continues to be a major challenge in stem cell and developmental biology⁵³.

Culturing pluripotent stem cells can be technically tricky⁵⁴. The culture conditions must preserve the pluripotent state of PSCs for extended periods while simultaneously ensuring efficient differentiation into preferred cell types

Furthermore, achieving high differentiation efficiency remains a significant hurdle in employing these cells for therapeutic purposes⁵⁵.

Ethical concerns surrounding the use of embryonic stem cells

The use of human embryonic stem cells (hESCs), which are isolated from a growing embryo, involves severe ethical concerns⁵⁶. This method involves the destruction of human embryos, a highly controversial issue, especially in the United States, where debates about the onset of human life are closely tied to discussions on abortion.

Some believe that embryos should be granted the same moral rights as adults, given that they can develop into human beings if implanted in a uterus. This has sparked debates over the moral status of the early embryo and the acceptability of using embryos for research. For those who hold this view, destroying an embryo to harvest stem cells is morally wrong and equates to taking a human life.

Safety and regulatory challenges for clinical use

The translation of pluripotent stem cell research into clinical therapies faces significant safety and regulatory hurdles.

Tumorigenicity: Pluripotent stem cells have the inherent ability to proliferate extensively, raising concerns about the potential for uncontrolled cell growth and the formation of tumors following transplantation. Researchers are actively developing strategies to mitigate this risk, such as ensuring complete and homogenous differentiation of PSCs into the desired cell type and implementing safety switches that can eliminate transplanted cells if necessary^57,58,59.

Off-target differentiation: Ensuring that transplanted PSC-derived cells differentiate into the intended cell type and do not give rise to unwanted cell types is important for safety and efficacy. Rigorous quality control measures and in vivo tracking of transplanted cells are essential. Any off-target cells that arise after implantation should be removed as soon as they are identified⁶⁰.

Immune rejection: The reprogramming process can sometimes lead to the expression of novel antigens. Genetic engineering can help overcome the immune barriers and immune rejection of stem cell-derived therapies⁶¹.

Regulatory classification: Regulatory agencies must decide whether stem cell therapies should be classified as drugs, biologics, or devices. This impacts the approval process and trial requirements.

FAQs

How do you identify pluripotent stem cells?

Identifying PSCs involves a combination of phenotypic markers, functional assays, and in vivo models.

• Phenotypic markers: Traditional markers such as OCT4, SOX2, and NANOG are commonly used to identify PSCs. However, none of these markers are exclusively expressed by PSCs, and their presence alone does not definitively confirm pluripotency. Interpretation of marker expression should consider the context and potential for expression in other cell types⁶².
• Functional assays: Teratoma formations remain a gold standard assay for assessing pluripotency⁶³.
• In vivo chimera formation: In animal models, the injection of PSCs into blastocysts can generate chimeric organisms. If the PSCs contribute to various tissues of the developing embryo, including the germline, this demonstrates that the cells are pluripotent⁶⁴.

How are pluripotent stem cells reprogrammed from adult cells?

Pluripotent stem cells can be reprogrammed from adult cells into induced pluripotent stem cells by introducing specific genetic factors.

• Yamanaka factors: In 2006, Shinya Yamanaka discovered that four transcription factors, such as OCT4, SOX2, KLF4, and c-MYC, could reprogram adult cells into iPSCs, which can differentiate into any cell type⁶⁵.
• Small molecules: Certain small molecules can enhance the reprogramming process or replace some factors, improving efficiency. For example, valproic acid helps boost reprogramming efficiency when used alongside Yamanaka factors⁶⁶.

References:

1.       Liu, G., David, B. T., Trawczynski, M., et al. Advances in pluripotent stem cells: History, mechanisms, technologies, and applications. Stem cell reviews and reports. 16, 3–32 (2020).

2.       Balboa, D., Iworima, D. G., & Kieffer, T. J. Human pluripotent stem cells to model islet defects in diabetes. Frontiers in endocrinology. 12, 642152 (2021).

3.       Yefroyev, D. A., & Jin, S. Induced pluripotent stem cells for treatment of Alzheimer’s and Parkinson’s diseases. Biomedicines. 10, 208 (2022).

4.       Singh, R. K., Binette, F., Seiler, M., et al. Pluripotent stem cell-based organoid technologies for developing next-generation vision restoration therapies of blindness. Journal of ocular pharmacology and therapeutics: the official journal of the Association for Ocular Pharmacology and Therapeutics. 37, 147–156 (2021).

5.       Saijo, Y., Nagoshi, N., Kawai, M., et al. Human-induced pluripotent stem cell-derived neural stem/progenitor cell ex vivo gene therapy with synaptic organizer CPTX for spinal cord injury. Stem cell reports. 19, 383–398 (2024).

6.       Romito, A., & Cobellis, G. Pluripotent stem cells: Current understanding and future directions. Stem cells international. 9451492 (2016).

7.       Keller, A., Dziedzicka, D., Zambelli, F., et al. Genetic and epigenetic factors which modulate differentiation propensity in human pluripotent stem cells. Human reproduction update. 24, 162–175 (2018).

8.       Deng, S., Xie, H., & Xie, B. Cell-based regenerative and rejuvenation strategies for treating neurodegenerative diseases. Stem cell research & therapy. 16, 167 (2025).

9.       Swain, N., Thakur, M., Pathak, J., et al. SOX2, OCT4 and NANOG: The core embryonic stem cell pluripotency regulators in oral carcinogenesis. Journal of oral and maxillofacial pathology: JOMFP. 24, 368–373 (2020).

10.   Mossahebi-Mohammadi, M., Quan, M., Zhang, J. S., et al. FGF signaling pathway: A key regulator of stem cell pluripotency. Frontiers in cell and developmental biology. 8, 79 (2020).

11.   Liu, S., Ren, J., Hu, Y., et al. TGFβ family signaling in human stem cell self-renewal and differentiation. Cell regeneration (London, England). 13, 26 (2024).

12.   Yu, M., Qin, K., Fan, J., et al. The evolving roles of Wnt signaling in stem cell proliferation and differentiation, the development of human diseases, and therapeutic opportunities. Genes & diseases. 11, 101026 (2023).

13.   Liu, J., Xiao, Q., Xiao, J.  et al.  Wnt/β-catenin signalling: function, biological mechanisms, and therapeutic opportunities.  Sig Transduct Target Ther.  7, 3 (2022).

14.   Zhang, S., & Cui, W. Sox2, a key factor in the regulation of pluripotency and neural differentiation. World journal of stem cells. 6, 305–311 (2014).

15.   Heurtier, V., Owens, N., Gonzalez, I.  et al.  The molecular logic of nanog-induced self-renewal in mouse embryonic stem cells.  Nat Commun.  10, 1109 (2019).

16.   Strebinger, D., Deluz, C., Friman, E. T., et al. Endogenous fluctuations of OCT4 and SOX2 bias pluripotent cell fate decisions. Molecular systems biology. 15, e9002 (2019).

17.   Ahmad, F., & Sachdeva, P. A consolidated review on stem cell therapy for treatment and management of Alzheimer’s disease. Aging medicine (Milton (N.S.W)). 5, 182–190 (2022).

18.   Zakrzewski, W., Dobrzyński, M., Szymonowicz, M., et al. Stem cells: past, present, and future. Stem cell research & therapy. 10, 68 (2019).

19.   Aguirre, M., Escobar, M., Forero Amézquita, S., et al. Application of the Yamanaka transcription factors Oct4, Sox2, Klf4, and  c-Myc  from the Laboratory to the Clinic. Genes. 14, 1697 (2023).

20.   Novelli G., Spitalieri P., Murdocca M., et al. Organoid factory: The recent role of the human induced pluripotent stem cells (hiPSCs) in precision medicine. Frontiers in Cell and Developmental Biology. 10, (2023).

21.   Yoshihara, M., Hayashizaki, Y., & Murakawa, Y. Genomic instability of iPSCs: Challenges towards their clinical applications. Stem cell reviews and reports. 13, 7–16 (2017).

22.   Marei, H. E., Althani, A., Lashen, S., et al. Genetically unmatched human iPSC and ESC exhibit equivalent gene expression and neuronal differentiation potential. Scientific reports. 7, 17504 (2017).

23.   Godini, R., Lafta, H. Y., & Fallahi, H. Epigenetic modifications in the embryonic and induced pluripotent stem cells. Gene expression patterns: GEP. 29, 1–9 (2018).

24.   Kim, K., Doi, A., Wen, B., et al. Epigenetic memory in induced pluripotent stem cells. Nature. 467, 285–290 (2010).

25.   Poetsch, M. S., Strano, A., & Guan, K. Human induced pluripotent stem cells: From cell origin, genomic stability, and epigenetic memory to translational medicine. Stem cells (Dayton, Ohio). 40, 546–555 (2022).

26.   Zhao, M. T., Chen, H., Liu, Q., et al. Molecular and functional resemblance of differentiated cells derived from isogenic human iPSCs and SCNT-derived ESCs. Proceedings of the National Academy of Sciences of the United States of America. 114, E11111–E11120 (2017).

27.   Marei, H. E., Althani, A., Lashen, S., et al. Genetically unmatched human iPSC and ESC exhibit equivalent gene expression and neuronal differentiation potential. Scientific reports. 7, 17504 (2017).

28.   Choi, J., Lee, S., Mallard, W., et al. A comparison of genetically matched cell lines reveals the equivalence of human iPSCs and ESCs. Nature biotechnology. 33, 1173–1181 (2015).

29.   Liu, X., Li, W., Fu, X., et al. The Immunogenicity and Immune Tolerance of Pluripotent Stem Cell Derivatives. Frontiers in immunology. 8, 645 (2017).

30.   Kim, H. S., Lee, J., Lee, D. Y., et al. Schwann cell precursors from human pluripotent stem cells as a potential therapeutic target for myelin repair. Stem cell reports. 8, 1714–1726 (2017).

31.   Sandoval, A. G. W., Gim, K. Y., Huang, J. T., et al. Applications of human pluripotent stem cell-derived skin organoids in dermatology. The Journal of investigative dermatology. 143, 1872–1876 (2023).

32.   Nakayama, N., Ravuri, S., & Huard, J. Rejuvenated stem/progenitor cells for cartilage repair using the pluripotent stem cell technology. Bioengineering (Basel, Switzerland). 8, 46 (2021).

33.   Harrison, S. P., Siller, R., Tanaka, Y., et al. Scalable production of tissue-like vascularized liver organoids from human PSCs. Experimental & molecular medicine. 55, 2005–2024 (2023).

34.   Kadota, S., Tanaka, Y., & Shiba, Y. Heart regeneration using pluripotent stem cells. Journal of cardiology. 76, 459–463 (2020).

35.   Okano, H., & Morimoto, S. iPSC-based disease modeling and drug discovery in cardinal neurodegenerative disorders. Cell stem cell. 29, 189–208 (2022).

36.   Brooks, I. R., Garrone, C. M., Kerins, C., et al. Functional genomics and the future of iPSCs in disease modeling. Stem cell reports. 17, 1033–1047 (2022).

37.   Liu, C., Oikonomopoulos, A., Sayed, N., et al. Modeling human diseases with induced pluripotent stem cells: from 2D to 3D and beyond. Development (Cambridge, England). 145, dev156166 (2018).

38.   Kim C. iPSC technology-Powerful hand for disease modeling and therapeutic screen. BMB reports. 48, 256–265 (2015).

39.   Hussen, B. M., Taheri, M., Yashooa, R. K., et al. Revolutionizing medicine: recent developments and future prospects in stem-cell therapy. International journal of surgery (London, England). 110, 8002–8024 (2024).

40.   Costamagna, G., Comi, G. P., & Corti, S. Advancing drug discovery for neurological disorders using iPSC-derived neural organoids. International journal of molecular sciences. 22, 2659 (2021).

41.   Xie, C., Liu, Y. Q., Guan, Y. T., et al. Induced stem cells as a novel multiple sclerosis therapy. Current stem cell research & therapy. 11, 313–320 (2016).

42.   Funakoshi, S., & Yoshida, Y. Recent progress of iPSC technology in cardiac diseases. Archives of toxicology. 95, 3633–3650 (2021).

43.   Nagoshi, N., Tsuji, O., Nakamura, M., et al. Cell therapy for spinal cord injury using induced pluripotent stem cells. Regenerative therapy. 11, 75–80 (2019).

44.   Yang, Y. P., Hsiao, Y. J., Chang, K. J., et al. Pluripotent stem cells in clinical cell transplantation: Focusing on induced pluripotent stem cell-derived RPE cell therapy in age-related macular degeneration. International journal of molecular sciences. 23, 13794 (2022).

45.   Oh, Y., & Jang, J. Directed differentiation of pluripotent stem cells by transcription factors. Molecules and cells. 42, 200–209 (2019).

46.   Silva, I. B. B., Kimura, C. H., Colantoni, V. P., et al. Stem cells differentiation into insulin-producing cells (IPCs): recent advances and current challenges. Stem cell research & therapy. 13, 309 (2022).

47.   Wu, X., Su, J., Wei, J., et al. Recent advances in three-dimensional stem cell culture systems and applications. Stem cells international. 9477332 (2021)

48.   Pellagatti, A., & Boultwood, J. Splicing factor mutations in the myelodysplastic syndromes: Role of key aberrantly spliced genes in disease pathophysiology and treatment. Advances in biological regulation. 87, 100920 (2023)

49.   Singh, S., Ahmed, D., Dolatshad, H., et al. SF3B1 mutations induce R-loop accumulation and DNA damage in MDS and leukemia cells with therapeutic implications. Leukemia. 34, 2525–2530 (2020).

50.   Pinjala, P., Tryphena, K. P., Prasad, R., et al. CRISPR/Cas9 assisted stem cell therapy in Parkinson’s disease. Biomaterials research. 27, 46 (2023).

51.   Park, S. H., & Bao, G. CRISPR/Cas9 gene editing for curing sickle cell disease. Transfusion and apheresis science: official journal of the World Apheresis Association: official journal of the European Society for Haemapheresis. 60, 103060 (2021).

52.   Rebs, S., Sedaghat-Hamedani, F., Kayvanpour, E., et al. Generation of pluripotent stem cell lines and CRISPR/Cas9 modified isogenic controls from a patient with dilated cardiomyopathy harboring a RBM20 p.R634W mutation. Stem cell research. 47, 101901 (2020).

53.   Fowler, J. L., Ang, L. T., & Loh, K. M. A critical look: Challenges in differentiating human pluripotent stem cells into desired cell types and organoids. Wiley interdisciplinary reviews. Developmental biology. 9, e368 (2020).

54.   Moy, A. B., Kamath, A., Ternes, S., et al. The challenges to advancing induced pluripotent stem cell-dependent cell replacement therapy. Medical research archives. 11, 4784 (2023).

55.   Wei, L., Yan, W., Shah, W., et al. Advancements and challenges in stem cell transplantation for regenerative medicine. Heliyon. 10, e35836 (2024).

56.   Volarevic, V., Markovic, B. S., Gazdic, M., et al. Ethical and safety issues of stem cell-based therapy. International journal of medical sciences. 15, 36–45 (2018).

57.   Dou, D., Lu, J., Dou, J., et al. Global regulatory considerations and practices for tumorigenicity evaluation of cell-based therapy. Regulatory toxicology and pharmacology: RTP. 156, 105769 (2025).

58.   Wang Z. Assessing tumorigenicity in stem cell-derived therapeutic products: A critical step in safeguarding regenerative medicine. Bioengineering (Basel, Switzerland). 10, 857 (2023).

59.   Kawamata, S., Kanemura, H., Sakai, N., et al. Design of a tumorigenicity test for induced pluripotent stem cell (iPSC)-derived cell products. Journal of clinical medicine. 4, 159–171 (2015).

60.   Hiyoshi, H., Sakuma, K., Asano, S., et al. Identification and removal of unexpected proliferative off-target cells emerging after iPSC-derived pancreatic islet cell implantation. Proceedings of the National Academy of Sciences of the United States of America. 121, e2320883121 (2024).

61.   Meissner, T. B., Schulze, H. S., & Dale, S. M. Immune editing: Overcoming immune barriers in stem cell transplantation. Current stem cell reports. 8, 206–218 (2022).

62.   Andrews, P. W., & Gokhale, P. J. A short history of pluripotent stem cells markers. Stem cell reports. 19, 1–10 (2024).

63.   Avior, Y., Biancotti, J. C., & Benvenisty, N. TeratoScore: Assessing the differentiation potential of human pluripotent stem cells by quantitative expression analysis of teratomas. Stem cell reports. 4, 967–974 (2015).

64.   Mascetti, V. L., & Pedersen, R. A. Contributions of mammalian chimeras to pluripotent stem cell research. Cell stem cell. 19, 163–175 (2016).

65.   Cho, H. E., Lee, S., Seo, J. H., et al. In vivo reprogramming using Yamanaka factors in the CNS: A scoping review. Cells. 13, 343 (2024).

66.   Duan, Q., Li, S., Wen, X., et al. Valproic acid enhances reprogramming efficiency and neuronal differentiation on small molecules staged-induction neural stem cells: Suggested role of mTOR signaling. Frontiers in neuroscience. 13, 867 (2019).