EGFR and head and neck squamous cell carcinoma: The N-glycosylation inhibitor 2-deoxyglucose (2DG) could change the N-glycosylation state of EGFR in HNSCC, induce the expression of the endoplasmic reticulum stress (ERS) markers CHOP and BiP, and finally affect the activity of EGFR; therefore, 2DG can enhance the antitumor effects of cisplatin and radiotherapy and overcome erlotinib resistance 25.