Primarily produced by T cells, (TH1 and TH17), LT-α shares redundant features with TNF-α, acting on TNFRI and RII, but the effects of LT-α are less robust than TNF-α.32,52 IL-9, produced by TH9 cells, TH2 cells Tregs, and TH17 cells, was originally defined as a T-cell growth factor, but is now known to have pleiotropic functions in allergy, cancer and autoimmune diseases.53 Thus, each of these cytokines can also be produced by TH17 cells. The gene discussed is IL9; the disease is Allergy.