MEN1 and Zollinger-Ellison syndrome: Whereas both the initial controlled studies with all the different PPIs (omeprazole, lansoprazole, esomeprazole, pantoprazole, rabeprazole), as well as a number of subsequent studies of series of patients with both sporadic ZES and ZES/MEN1 patients, reported that PPIs could control the acid hypersecretion in nearly all patients, except those who would or could not regularly take the medication, both initially and long-term [33,59,65,67,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95].