The aim of the study was to look for the association of FPGS 2752 G > A (rs1544105), FPGS 1994 A > G (rs10106), and GGH 452 C > T (rs 11545078), GGH -401C > T (rs 3758149) gene polymorphisms with methotrexate (MTX) treatment response and MTX-induced adverse events in South Indian Tamil patients with rheumatoid arthritis (RA).