This is a trypsin inhibitor, its physiological function is to prevent the trypsin-catalyzed premature activation of zymogens within the pancreas. Defects in SPINK1 are a cause of pancreatitis (PCTT) [MIM:167800]. A disease characterized by the presence of calculi in pancreatic ducts. It causes severe abdominal pain attacks. Defects in SPINK1 are the cause of susceptibility to tropical calcific pancreatitis (TCP) [MIM:608189]. TCP is an idiopathic, juvenile, nonalcoholic form of chronic pancreatitis widely prevalent in several tropical countries. It can be associated with fibrocalculous pancreatic diabetes (FCPD) depending on both environmental and genetic factors. TCP differs from alcoholic pancreatitis by a much younger age of onset, pancreatic calcification, a high incidence of insulin dependent but ketosis resistant diabetes mellitus, and an exceptionally high incidence of pancreatic cancer.