Omeprazole and CYP2C19 polymorphism: effects of long-term treatment on gastrin, pepsinogen I, and chromogranin A in patients with acid related disorders. - Sagar, M.; Bertilsson, L.; Stridsberg, M.; Kjellin, A.; Mårdh, S.; Seensalu, R. (Alimentary Pharmacology & Therapeutics, 2000)