Since METTL3 is known to regulate TGF-β signaling in lung and gastric cancers [41, 42], and SMAD4 is a critical mediator of TGF-β signaling, we checked the expression levels of a few downstream effectors of SMAD4-dependent TGF-β signaling in METTL3-depleted SCC-25 cells, by western blot analysis. The gene discussed is SMAD4; the disease is gastric cancer.