GPC1 and colorectal cancer: Circulating glypicans have been proposed as fluid biomarkers for different non CNS-associated pathologies: GPC-1 can be detected in serum of patients with pancreatic cancer10, GPC-3 is a marker for hepatocellular carcinoma11 and GPC-4 has been described as a survival marker in colorectal cancer and breast cancer12,13, as well as for cardiovascular disease14,15.