CD8A and rheumatoid arthritis: Three distinct CD8+ CD69+CD103+ TRM cell populations were identified within inflamed arthritic joints: cytotoxic and Treg-like TRM cells, found in the synovial joint of both PsA and RA patients, while type 17-like TRM cells and type 17-like CD8+CD103 T cells were specifically enriched in PsA patients (62).