<prompt> Zollinger- Ellison syndrome is due to increased secretion ofGastrinSecretinVIPCholecystokinin  <response>: Gastrinoma Zollinger-Ellison syndrome is a condition that includes:Fulminating ulcer diathesis in the stomach, duodenum or atypical sites; Recurrent ulceration despite adequate therapy; and Non-beta islet cell tumours of the pancreas gastrinomaRef: Bailey and Love 27e pg: 850 