CD8A and psoriatic arthritis: Additionally, since the pMIXED peptides technically possessed the optimal HLA-B*07 consensus sequence, with the Pro in P2 and the Leu in PΩ, we evaluated the CD8+ T cell responses in 12 HLA-B*07 subjects (6 HD, 2 patients with AS, 2 with psoriatic arthritis (PsA) and 2 with rheumatoid arthritis (RA)) [39,40].