While additional research is necessary to gain a clearer insight into how TRM cells develop within OA joint tissues and influence the onset of irAEs, the identification of PD1+ TRM in OA, along with the observation that OA is a significant risk factor in irAE-arthritis, supports the classification of the OA joint as an immunological niche poised for activation, given an appropriate trigger [27]. This evidence concerns the gene PDCD1 and arthritic joint disease.