The human PRDM1 (Blimp1) locus has been identified as a susceptibility gene for development of the autoimmune diseases systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA; Gateva et al, 2009; Raychaudhuri et al, 2009; Zhou et al, 2011). This evidence concerns the gene PRDM1 and rheumatoid arthritis.