TNFRSF1A and rheumatoid arthritis: In a study that enrolled 58 RA patients receiving infliximab, six polymorphisms, 36A > G in TNFR1; 676T > G in TNFR2; −857C > T, −308G > A, −238G > A and 489G > A in TNF-α gene and their relationship to therapeutic efficacy were determined.