Signature cytokines of Th17 cells include IL-17A, IL-17F, IL-22, and IL-26 (specific for humans) and these canonical cytokines produced by the classical Th17 (CD4+ IL-17 producing cells) and non-Th17 cells including γδ-T cells and innate lymphoid cells play critical roles in regulating tissue homeostasis and inflammation as well as antimicrobial responses upon infections caused by pathogens. This evidence concerns the gene IL22 and infection.