EGFR and small cell lung carcinoma: Multiple EGFR TKI resistant mechanisms have been documented, e.g. the appearance of new EGFR mutations including T790M or C797S mutations [6,7], the activation of a bypass signaling pathway [8,9], epithelial-mesenchymal transition (EMT) or histological transition to small cell lung cancer (SCLC) [10,11].