FAT4 and cancer: Finally, among the proteins selected by the DAPC analysis that were less abundant in bile from these patients were pancreatic alpha-amylase (AMY2A), previously found in bile [38], ectonucleotidase pyrophosphatase/phosphodiesterase 7 (ENPP7), also known as alkaline sphingomyelinase (alk-SMAse), which is less abundant in bile from patients with pancreatobiliary malignancies [75], and protocadherin fat 4 (FAT4), a presumed tumor suppressor gene frequently mutated and silenced in solid tumors [76].