CXCL8 and Alzheimer disease: Overall, a significant association of IL-8 gene –251T>A polymorphism with increased risk of AD was observed (allele, A vs T: OR = 1.32, 95%CI = 1.16–1.50; homozygous, AA vs TT: OR = 1.70, 95%CI = 1.21–2.21; heterozygous, TA vs TT: OR = 1.37, 95%CI = 1.12–1.69; recessive, AA vs TA+TT: OR = 1.40, 95%CI = 1.12–1.75).