EGFR and small cell lung carcinoma: Another etiology for TKI resistance to therapy is the transformation of NSCLC (about10%) to small cell lung cancer (SCLC), which can be seen concurrently with EGFR alterations [37,38,39] (https://www.nccn.org/professionals/physician_gls/pdf/nscl.pdf; accessed on 29 August 2024).