RBM15 and chronic obstructive pulmonary disease: Differential analysis of 23 m6A methylation regulators highlighted that several, including METTL3, RBM15, RNM15B, CBLL1, YTHDC2, YTHDF1, YTHDF2, HNNRPC, LPPPRC, RBMX, FTO and ALKBH5, were significantly overexpressed in COPD patients.