CTRB1 and familial pancreatic carcinoma: In addition, five down-regulated proteins identified in pancreatic cancer juice (carboxypeptidase A2, chymotrypsinogen B, elastase-3A, elastase-3B and trypsin-1) was also down-regulated in pancreatic cancer tissues compared with pancreatitis and normal pancreas tissues as described by Shen et al. [9].