Prior GWAS have identified several shared genetic loci (including PSORS2, PSORS3, and PSORS4) and mutual genes (including CDKAL1, ST6GAL1, PTPN22, and JAZF1) that link psoriasis and the susceptibility to diabetes.402,403 Moreover, the increased key cytokines in psoriasis, such as IL-23, IL-17, IL-1β, IFN-γ, and TNF-α can damage islet β cells in a separate and synergistic manner. Here, PTPN22 is linked to psoriasis.