In addition, we examined CYP19A1 protein expression and the intratumoural E2 concentration in lung lesions of KO-NC and KO-METTL3 tumours in the tail-vein injection model, and the results showed that CYP19A1 protein and E2 levels were significantly decreased after METTL3 knockout (Fig. 5M-N). The gene discussed is CYP19A1; the disease is neoplasm.