IL17A and psoriasis: CD8+TRM cells have been identified to exacerbate skin inflammation in the psoriatic skin by producing IL-17A.414–416 Moreover, IL-22 produced by CD69+CD4+TRM cells also enhanced psoriatic inflammation by targeting epidermal keratinocytes, a predictive feature of psoriatic skin.417,418 Therefore, strategies for eliminating TRM cells may be effective in treating psoriasis.