CCL2 and AIDS: In the largest longitudinal study to date, drawing from pre-cART neurocognitive data from HIV + and seronegative participants in the Multicenter AIDS Cohort Study (MACS), Levine et al. [57•] did find evidence for a small effect of MIP-1α/CCL3 and MCP-1/CCL2 genotype on neurocognitive functioning over time among HIV + cases only, but the magnitude of this effect was small.