IL-24 is a secreted glycoprotein belonging to the IL-10 structural family of cytokines. It is produced by a variety of cell types, including B cells, CD4+ cells, NK cells, lymph node DCs, monocytes, and melanoma cells. IL-24 can signal through the IL20R1/IL20R2 and IL22R1/IL20R2 receptors to initiate a signaling cascade, which includes the induction of JAK1/STAT3 phosphorylation. IL-24 is, functionally, a pleiotropic protein, but is generally characterized as an anti-cancer cytokine that can selectively inhibit growth of a wide variety of human cancer cells through activities that include: the induction of differentiation and apoptosis; and the suppression of angiogenesis and cell proliferation. Recombinant Human IL-24 is an 18.9 kDa glycoprotein that contains 161 amino acid residues, including a C-terminal His-tag.