METTL14 and rheumatoid arthritis: In this study, we firstly detected the expression of m6A methylation-associated genes (METTL3, FTO, ALKBH5, METTL14, YTHDF1, and YTHDF2) in PBMCs from RA patients and found that METTL3 was obviously upregulated in RA compared with healthy controls.