Additionally, we found that CCL3L1 copy number and CCR5 genotypes that were associated with reduced cell mediated immune responses in HIV-negative individuals of European descent were similar to those that were associated with a rapid rate of disease progression in HIV+ European Americans [20], suggesting that the CCL3L1-CCR5 axis might play an important role in mediating cellular immune responses relevant to AIDS pathogenesis. This evidence concerns the gene CCR5 and AIDS.