Discernable genetic variation among people and populations has an important role in infectious disease epidemics, including that of acquired immune deficiency syndrome (AIDS). Genetic association analysis of several large AIDS cohorts implicate 14 AIDS restriction genes, polymorphic variants in loci that regulate HIV-1 cell entry, acquired and innate immunity, and cytokine defenses to HIV-1. The influence and translational impact of these genes on individual and population sensitivity to AIDS is considerable.