Previous studies have reported that acquired EGFR p.T790M (c.2369 C > T; p.Thr790Met) and p.C797S (c.2389 T > A and c.2390G > C, p.Cys797Ser) mutations are closely associated with osimertinib resistance in NSCLC [28, 29]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.