Anti-HIV drugs have to act against the virus but not cause too much harm to human cells. This means that they must be designed to target specific stages in the virus life-cycle that differ from the life-cycle of human cells. A thorough understanding of HIVs life-cycle is thus important as the basis for designing effective, well-targeted anti-HIV drugs.

HIV has nine genes which contain all the information to enable it to infect healthy human cells and then use the infected cells to create more virus. It is these genes or the proteins that they encode that are the targets of anti-HIV drugs.