Cyclooxygenase-2 gene polymorphisms and risk of Alzheimer's disease: A meta-analysis

C-allele of rs20417 (− 765G > C) polymorphism was associated with reduced risk of AD, and might be a protective factor. Because of the limit sample and heterogeneity, the association between rs689466 polymorphism and AD risk should be treated with caution. To further confirm this relationship, larger-scale and better-designed studies should be conducted in the future.