EGFR and colorectal carcinoma: In colorectal carcinoma, where EGFR is overexpressed by a variable but high percentage of patients and EGFR targeted therapy is a mainstay of treatment [224], but EGFR expression levels do not necessarily correlate with therapy efficacy, perhaps owing to inconsistencies in immunohistochemical methods [225], sEV-expressed EGFR was identified as part of an A33+ colorectal carcinoma-specific proteomics signature [226]; however, no specific claims as to its applicability in the clinic were made.