PRF1 and rheumatoid arthritis: In Figures 3B–E, a comparison between RA-LJ and OA reveals two key modules with 14 upregulated genes (CST7, CD8A, GEMK, GZMH, GZMA, GZMB, PRF1, CD3D, CXCL9, NKG7, CD2, CD247, ITGAL, CCL5) and three downregulated genes (SOX8, ZIC1, and POU3F3).