The involvement of anti-PD-1 antibodies in the occurrence/exacerbation of psoriasis may be related to the following mechanisms: (i) Anti PD-1 therapy enhances the cytotoxic effect of CD103+TRMs;84 (ii) Anti PD-1 antibody enables the amplification of TRM clones and enhances the expression of IFN-γ and IL-17 that can initiate/exacerbate psoriasis;47 (iii) PD-1 antibody blockade enhances the interaction and co-activation of TRM with circulating memory cells.85 Here, IL17A is linked to psoriasis.