METTL3 and hepatocellular carcinoma: It has been reported that the interaction of SMAD2/3 with m6A writer complexes promotes m6A deposition on a subset of transcripts.[15] We then confirmed the binding of SMAD3 and METTL3, one of the important components of m6A writer complexes, in HCC progression (Figure 1A,B; Figure S1A, Supporting Information left panel).