For sample size, the studies were stratified into two subgroups, one comprising studies with more than 200 subjects and one with fewer than 200 subjects. In these subgroups, significantly reduced HIV-1 infection of 5/5 homozygous (OR = 0.69, 95% CI = 0.50-0.94, and p = 0.02) and 5-repeat allele carriers (OR = 0.82, 95% CI = 0.68-0.98, and p = 0.03) was found in the subgroup with a sample size of more than 200 subjects, but not in the subgroup with fewer than 200 subjects (Table S2 ).