METTL3 and cancer: METTL3, as the first reported m6A writer, is a major methyltransferase, and its expression is up‐regulated in different cancers such as gastric cancer, nasopharyngeal carcinoma, cervical cancer and liver cancer.35, 36, 37, 38 In the current research, highly expressed METTL3 was further confirmed in DLBC, CHOL, THYM and liver cancer, and the level of METTL3 was determined to be negatively correlated with the overall survival.