Bagheri et al. (22) believe that the MTHFR 677C/T SNP is associated with the genetic susceptibility of African RA patients under only the recessive model, whereas in the Asian population both the T allele and TT genotype are associated with RA, and the CC genotype of the 1298A/C SNP is associated with RA in the recessive model. Here, MTHFR is linked to rheumatoid arthritis.