EGF and neoplasm: Under its ligand EGF stimulation, EGFR triggers a series of downstream signaling pathways, including PI3K-AKT, Ras-MAPK, and signal transducers and activators of transcription (STAT) signaling pathways, which are involved in many stages of tumor progression, such as cell proliferation, angiogenesis, invasion, migration, metastasis and apoptosis (Hong et al., 2014).