METTL3 and rheumatoid arthritis: Given the effects of these key genes involving in m6A methylation modification on the pathogenesis of many disease [14, 24], we firstly detected the expression of m6A methylation-associated genes (METTL3, METTL14, WTAP, FTO, ALKBH5, and YTHDF2) in the peripheral blood from RA patients and showed that the expression of ALKBH5, FTO, and YTHDF2 in the peripheral blood from RA patients was significantly lower than CON, while the expression of METTL3, METTL14, and WTAP was unchanged.