A third type of inducible T cell immunity involves IL-17 production, a cytokine initially found to play a central role in inflammation and autoimmunity and now recognized as an important cytokine involved in normal responses to pathogens, such as those of the respiratory tract (Lu et al., 2008; Sonnenberg and Weiner, 2009), and in protective immunity induced by vaccination (Bettelli et al., 2007; Moffitt et al., 2011). Here, IL17A is linked to Autoimmunity.