EGFR and small cell lung carcinoma: For instance, SCLC Transformation from NSCLC has been reported in 3%–14% of patients with EGFR-mutant NSCLC who gained resistance to first- and second-generation EGFR-TKIs [647, 653], and in 5%–20% of those with acquired resistance to the third-generation EGFR-TKI, osimertinib [646, 654], representing that SCLC transformation can happen regardless of the EGFR-TKIs generation.