Function as an agonist of NF-kappa B activation through the orphan IL-1-receptor-related protein 2. Could constitute part of an independent signaling system analogous to interleukin-1 alpha (IL-1A), beta (IL-1B) receptor agonist and interleukin-1 receptor type I (IL-1R1), that is present in epithelial barriers and takes part in local inflammatory response.
Highly expressed in tissues containing epithelial cells: skin, lung, stomach and esophagus. In skin is expressed only in keratinocytes but not in fibroblasts, endothelial cells or melanocytes. Up-regulated in lesional psoriasis skin.