IL-19 shares a receptor complex with IL-20, indicating that the biological activities of these two cytokines overlap and that both may play an important role in regulating development and proper functioning of the skin. Unlike IL-10, which forms an intercalated dimer, IL-19 is a monomer comprised of seven amphipathic helices, A-G, creating a unique helical bundle. rHu IL-19 produced in E. coli is a single, non-glycosylated polypeptide chain that contains 154 amino acids and has a molecular mass of 17.91 kDa.