Treatment with the METTL3‐14‐WTAP activator effectively suppressed tumor growth in vivo (Figure 9H–J) and stimulated the differentiation of thyroid cancer through the METTL3‐SETMAR‐SMARCA2‐TTF axis, which was confirmed by increased immunohistochemical staining for SETMAR, SMARCA2 and thyroid differentiation markers in tumors after treatment (Figure S12A, Supporting Information). The gene discussed is RHOH; the disease is thyroid cancer.