EGFR and non-small cell lung carcinoma: Apart from such individual genetic changes, a small subset of EGFR‐mutant NSCLC patients develop resistance to EGFR‐TKI therapy by undergoing histological transformation to small‐cell lung cancer (SCLC) and become sensitive to standard SCLC treatment (Sequist et al, 2011; Niederst et al, 2015).