HLA-DRB1 and rheumatoid arthritis: They genotyped HLA-DRB1, HLA-DQA1, HLA-DQB1, MHC class I chain-related gene A (MICA) transmembrane polymorphism alleles, and TNFa-e, D6S273, HLA–B–associated transcript 2 (BAT2), and D6S2223 microsatellites in 78 RA patients who received IFX treatment.