EGFR and head and neck cancer: Several studies have addressed the possibility of phosphorylation and glycosylation of sEV proteins as cancer biomarkers, for example, phospho-EGFR in head and neck cancer [173], phospho-AKT and -ERK1/2 in non-small-cell lung cancer [174], and EGFR-specific N-glycan in colorectal cancer [175].