EPAS1 and hereditary clear cell renal cell carcinoma: Although MTHFD2 has not been identified as an m6A methylase by definition, MTHFD2 expression is significantly increased in renal cell carcinoma and is involved in regulation the overall level of m6A methylation, especially HIF-2α m6A methylation, promotes HIF-2α expression, thus promotes aerobic glycolysis of tumor cells and tumor progression.