hypothesized that exosomes specifically the ones that are secreted from cancer cells contain glypican1 protein (GPC1); thus, exosomal GPC1 can be utilized as a biomarker for breast and pancreatic cancer.[140] Their hypothesis is based on the fact that GPC1 is a membrane‐bound protein that is overexpressed in breast and pancreatic tumors. This evidence concerns the gene GPC1 and familial pancreatic carcinoma.