Interleukin 15 (IL-15) belongs to the 4-α-helix bundle family of glycoprotein cytokines that include IL-2, IL-3, IL-4 and IL-21. It exerts profounds effects on the proliferation, survival and differentiation of NK cells and T cells. IL-15 is produced in a variety of cell types like monocytes, dendritic cells, macrophages, keratinocytes, fibroblasts, and nerve cells. Its production is under complex control with regulation occurring at the level of transcription, translation, intracellular trafficking and translocation. (Upgraded 01/2020)...