The different expression of METTL3 increases the levels of expression of critical genes regulating the autophagy pathway, such as autophagy-related gene -5 (ATG-5) and ATG-7, and has proven that alterations in autophagy, mediated by METTL3, can present different degrees of gefitinib resistance in NSCLC, the mechanism of which is possibly connected tightly with temporal ITH (Figure 4) [42]. The gene discussed is METTL3; the disease is non-small cell lung carcinoma.