FCGR2A and rheumatoid arthritis: In our study, we analyzed the joint influence of the FCGR2A rs1801274-G (FCGR2A-p.131Arg) and FCGR3A rs396991-A (FCGR3A-p.158Phe) low-affinity alleles on the effectiveness of ABA in patients diagnosed with RA, since BTs, as we have already described, can be affected by both these SNPs.