IL22 and psoriasis: The activation of T helper (Th) cells including Th1, Th17, and Th22 cells trigger the inflammatory process of psoriasis and upregulate an array of proinflammatory cytokines [10], among, Th17 cells are the primary source of IL-22, which principally targets keratinocytes and orchestrates its effect through the activation of mitogen activated protein kinases (MAPKs) and signal transducer and activator of transcription 3 (STAT3) [11].