In addition to acquired mutations in EGFR, several other mechanisms, such as bypass mechanisms in EGFR-mediated signaling [40], epithelial-mesenchymal transition (EMT) [32, 41, 42], pathological transformation to small cell lung cancer [43], immune escape [44], and downstream activation of the RAS or PI3K pathways [31] have been reported. This evidence concerns the gene EGFR and small cell lung carcinoma.