CCL5 and Alzheimer disease: The meta-analysis revealed a significant association between the CCL5 − 403G/A polymorphism and AD under the allelic model (A vs G: OR = 1.25, 95% CI = 1.02–1.52, P = .03), heterozygous model (AG vs GG: OR = 1.40, 95% CI = 1.08–1.80, P = .01) and dominant model (AA + AG vs GG: OR = 1.38, 95% CI = 1.08–1.76, P = .01) in a fixed-effect model.