EGFR and neoplasm: Abnormal activation of the epidermal growth factor receptor (EGFR) signaling pathway has been reported in NSCLC, which leads to the activation of subsequent intracellular signaling pathways, including the phosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase 1 (MAPK) signaling pathways, which serve important roles in the proliferation, differentiation, migration and apoptosis of tumor cells (5,6).