Description: Human IL-15 is a ~15 kDa factor with its mRNA found in a wide variety of cells including peripheral blood mononuclear cells (PBMC), placenta, skeletal muscle, kidney, lung, liver and heart. It is produced most abundantly by epithelial cells and monocytes. IL-15 shares many biological properties with IL-2 including stimulation of CTLL proliferation, and in vitro generation of alloantigen-specific cytotoxic T cells and non-antigen specific lymphokine activated killer (LAK) cells.