For human glioblastoma U251 cells (Figure8A; Figure S10A,B, Supporting Information) and human colon cancer HCT116 cells (Figure 8B; Figure S10C,D, Supporting Information), the results strongly supported that the m6A writers METTL3 and METTL14 were down‐regulated upon the addition of bile acids, especially at high concentrations. The gene discussed is METTL3; the disease is glioblastoma.