GAST and gallstones: Other factors, such as cholelithiasis (gallstones) and reflux disease, are perhaps of interest in terms of potential mechanistic hypotheses, such as inflammation of the pancreas before cancer as a result of cholelithiasis or a hypothetical link between medication by proton pump inhibitors, such as omeprazole in reflux disease, and the effect of increased levels of gastrin on the state of the pancreas43.