GSTM1 and anemia: We found that RA patients had substantially reduced levels of RBC, Hb, and MPV compared to controls, which was consistent with previous studies [5,6,38,39]. Multiple studies have linked the presence of anemia with severe structural damage, poor joint function, and increased disease activity in RA patients compared to controls [5-8]. Furthermore, normochromic and normocytic anemia were found in Cameron RA patients [40].