Carbohydrate antigen 19-9

CA19-9 is a mucin-type carbohydrate protein tumor marker, which is a glycolipid on the cell membrane, and its molecular weight is larger than that of 1000kD. It is the most sensitive marker for pancreatic cancer reported so far. It exists in the form of salivary mucin in serum and is distributed in normal fetal pancreas, gallbladder, liver, intestine and normal adult pancreas and bile duct epithelium. It is a gastrointestinal tumor-associated antigen present in the blood circulation.