METTL1 and esophageal squamous cell carcinoma: Recent studies have identified METTL1 and WDR4, components of the m7G methyltransferase complex, as negative regulators of MTORC1-mediated autophagy in ESCC; thus, METTL1 and its downstream signaling axis, the RPTOR/ULK1/autophagy pathway, may become novel regulators of autophagy in ESCC cells [65].