PKNOX1 and AIDS: Here, we evaluated the polymorphisms in previously tested candidate genes CCR5, CCR2, MCP-1, TNFA, APOE and CCL3, as well as a polymorphism in the novel candidate gene PREP1, for their association with HAD in participants of the Amsterdam Cohort Studies of HIV infection and AIDS (ACS) and the AIDS therapy evaluation in The Netherlands (ATHENA) observational cohort.