MEN1 and gastroesophageal reflux disease: The study included a large number of patients (n = 303), they resembled most smaller series in the literature in all characteristics, and the cohort had all aspects of the disease, including different tumor extents, with or without MEN1, with or without previous gastric acid reduction surgery, with and without different degrees of GERD, all of which have been reported to affect the success of medical acid antisecretory therapy in ZES patients.