The m7G regulatory factors methyltransferase 1 (METTL1) and WD Repeat Domain 4 (WDR4) participate in the regulation of various cancer types, including HNSCC, liver cancer, bladder cancer, and lung cancer, by changing the m7G modification levels of miRNAs and tRNAs 18,19. This evidence concerns the gene WDR4 and urinary bladder carcinoma.