CYP2C19 and gastroesophageal reflux disease: Since PPIs are commonly used in the treatment of reflux esophagitis, gastroesophageal reflux disease (GERD), Zollinger–Ellison syndrome, non-ulcer dyspepsia, and NSAID-related damage, the healing process in the therapy of these diseases was predictably affected by CYP2C19 genotype [91, 93, 96, 97].