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. The gene discussed is WDR4; the disease is urinary bladder cancer.