ATP12A and gastroesophageal reflux disease: Proton pump inhibitors (PPIs) are used to treat a variety of gastro-intestinal conditions like erosive esophagitis due to gastroesophageal reflux disease (GERD), hypersecretory conditions including Zollinger Ellison syndrome, Helicobacter pylori infection, non-steroidal anti-inflammatory drugs (NSAIDs)-induced ulcers, prevention of re-bleeding in peptic ulcers, and prophylaxis for stress ulcers in critically ill patients.