Previous studies have reported that GPC-1 is specificallyenriched on cancer-cell-derived exosomes.12,13 It has been found that PC patients express higher levels of GPC-1on their exosomes than healthy controls with high specificity andsensitivity for PC.14 Other exosome-basedproteins such as epidermal growth factor receptor (EGFR)4 and epithelial cellular adhesion molecule (EpCAM)15 also show high accuracy and selectivity forPC detection. This evidence concerns the gene EPCAM and pachyonychia congenita.