TLR4 and rheumatoid arthritis: Thus, GzmK+CD8+T cells exert their pro-inflammatory function directly and through GzmK-mediated CS, TLR4 signaling, and CXCR4–CXCL12 interactions, thereby exaggerating inflammation and chronic inflammatory diseases, including AIDs, such as rheumatoid arthritis (RA), and can be targeted to overcome these conditions [315,316,317].