GAST and neoplasm: Among gastrointestinal mucinous neoplasms, GNAS mutations are prevalent in intraductal papillary mucinous neoplasms, a type of invasive pancreatic cystic neoplasm that has the potential to progress into appendiceal mucinous tumors or pancreatic adenocarcinoma, where Gαs‐promoted signaling is essential for tumor growth [156, 157, 158, 159].