The activated T helper lymphocytes proliferate and release cytokines: after stimulation by antigen and APC, the Th0 cells begin to produce interleukin (IL)-2. Meanwhile, Th cells differentiate into Th1, Th2 and Th17 according to the nature of the cytokines present in the activation site: IL-12 produced by macrophages and type I Interferon (IFN) or NK cells induce differentiation towards Th1, IL-4 produced by NK1.1 + T cells, basophils or mast cells induce differentiation towards Th2, and IL-1b, IL-23, TGFβ and IL-6 induce differentiation towards Th17 [9]. Th17 cells produce IL-17 and IL-22, and antigen-induced Treg (iTreg).