EGFR and neoplasm: Thus, by inhibiting the tyrosine kinase activity required in the process of tumor cell differentiation and metastasis, EGFR-TKI targeted therapy is able achieve the effect of “killing” tumor cells.30,31 Therefore, gefitinib, as a EGFR-TKI, inhibits kinase activity by competitively interacting with the ATP-binding site of EGFR, thus preventing auto-phosphorylation and thereby blocking EGFR-induced activation of downstream signaling, which leads to apoptosis in cells with EGFR mutations.