The expression of other well‐established cancer‐associated proteins such as HER‐2, programmed death ligand 1 (PD‐L1), prostate‐specific antigen (PSA), glypican‐1 (GPC1), and CD147 also have been analyzed in exosomes to utilize these exosomal proteins as a biomarker for GI cancer. Here, ERBB2 is linked to cancer.