They demonstrated expanded GZMB+ populations highly expressing GNLY that were present in the RA ST, and stimulation of ACPA + RA CD8+ T cells with citrullinated antigens in the context of HLA class I induced cell proliferation, clonal expansion, and expression of cytotoxic mediators and chemokine receptors, demonstrating that CD8+ cells targeting citrullinated proteins may contribute to synovitis and joint tissue destruction [39]. The gene discussed is PRTN3; the disease is rheumatoid arthritis.