Modulates negatively TGFB1 signaling in keratinocytes.
Widely expressed with high level in uterus, aorta, heart, lung, trachea, placenta and in fetal heart, kidney, liver, spleen and lung. Expressed by CD34(+) acute myeloid leukemia cell lines, T-cell lines, activated T-lymphoblasts, endothelial cells and activated platelets. Isoform 5 is expressed in placenta. Isoform 1 is expressed in keratinocytes and placenta.
Belongs to the protease inhibitor I39 (alpha-2-macroglobulin) family.
N-glycosylated. 2 forms of 150 (p150) and 120 kDa (p120) exist due to proteolytic degradation from a 180 kDa form.