EGFR and cancer: The aberrant activation of epidermal growth factor receptor (EGFR), a member of the ErbB family, and the consequent abnormal activation of its downstream signaling pathways are widely recognized as hallmarks in the pathogenesis of various cancers, including lung adenocarcinoma, glioblastoma (GBM), and colorectal cancers [1, 2, 3, 4].