In keratinocytes, STAT3 has a central role in response to various inflammatory cytokines in psoriasis, such as IL-6, IL-17, IL-21, IL-19, IL-22, etc. STAT3 activation in keratinocytes inhibited cell differentiation, promoted proliferation and production of antimicrobial peptides [78, 79]. The gene discussed is IL17A; the disease is psoriasis.