MTHFR and rheumatoid arthritis: Seven SNPs were considered candidates for RA susceptibility which are TNFB (rs909253), BsmI (rs1544410), TaqI (rs731236), MTHFR C677T (rs1801133), TGFβ1 (rs1982073), MTHFR A1298C (rs1801131), and ApaI (rs7975232).