A method, system, and apparatus for treating a patient with HIV. A vector can be modified from a thymidine kinase gene. The modified vector is expressed in the presence of tat RNA. The modified vector is then package and delivered to HIV-infected cells. The replication of HIV is inhibited by eliminating infected cells in the presence of Ganciclovir. Modified cells are then selected utilizing transient tat RNA transfection and GFP expression. Vector-modified stem cells are then selected for transplantation back into the patient, thereby producing a normal immune system in the patient when the modified vector remains dormant in the absence of HIV tat.