T790M is frequently regarded as a resistance mutation in EGFR-TKIs [42], and one study concluded that afatinib was less beneficial than third-generation osimertinib in terms of the survival of patients with NSCLC who obtained a T790M resistance mutation after failing first-line EGFR-TKI medication [43]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.