IL17A and psoriasis: For instance, S.epidermis colonization shapes the skin’s T cell network, bolstering cutaneous CD8+ T cells to produce interferon gamma, (IFNγ) and interleukin-17A (IL-17) effector functions which protect against pathogenic bacteria, Leishmania and C. albicans and also prevents exposure to S.aureus, hindering inflammatory diseases, which are strongly associated with psoriasis [54].