In conclusion, in antiretroviral-experienced patients with HIV-1 RNA <50 copies/mL and CD4+ counts >500 cells/mm3, substituting abacavir for hyperlipidemia-associated PIs in HAART regimens improves lipid profiles and maintains virologic suppression over a 28-week period, and it simplifies treatment. This evidence concerns the gene CD4 and hyperlipidemia.