HRH2 and Zollinger-Ellison syndrome: In an NIH study [302], body iron stores (serum iron, ferritin, transferrin, iron/transferrin ratio, complete blood counts) were assessed in 109 consecutive ZES patients without any previous gastric resections who were being treated long-term with either PPIs (78%), histamine H2 receptor antagonists (10%), or receiving no acid anti-secretory treatments because there were post curative gastrinoma resection (10%).