Although the CPIC® guidelines recommend consideration of 50-100% dose escalation for individuals with CYP2C19 normal (NM), rapid (RM), and ultra-rapid metabolizer (UM) status only for select conditions (e.g., H. pylori infections, erosive esophagitis) for which ample published data were available, it is the opinion of the authors that these recommendations can and should be extended to other clinical indications for PPI use (e.g., eosinophilic esophagitis, gastroesophageal reflux disease) for which less published data was available at the time of guidelines publication. Here, CYP2C19 is linked to gastroesophageal reflux disease.