On the other hand, polymorphisms in IL23R, TNFAIP3, PTPN22 (tyrosine-protein phosphatase non-receptor type 22), IL12B, RUNX1 (CD8-lymphocyte activation and differentiation), IL13, KIR (killer-cell immunoglobulin-like receptor), and MAGI1 genes have shown association with psoriatic arthritis [10,58]. Here, CD8A is linked to psoriatic arthritis.