Interleukin 22 (IL-22) is an α-helical cytokine, predicts a molecular mass of 16.9 kDa. It is produced by T-helper (Th) -17 cells, γδ T cells, NKT cells and newly described innate lymphoid cells (ILCs) . Effects involve stimulation of cell survival, proliferation and synthesis of antimicrobials including S110, Reg3β, Reg3γ and defensins.