Various resistance mechanisms for EGFR-TKIs have been reported in previous research, including T790M point mutations, EGFR amplification, ERBB2 amplification, small cell lung cancer transformation, MET amplification, PI3K mutations, epithelial-mesenchymal transition (EMT), BRAF mutations, and KRAS mutations [3,4,5,6]. Here, EGFR is linked to small cell lung carcinoma.