While CD4+ T cells are known to be targeted and depleted during the course of HIV infection, there is also a dramatic and immediate impact on γδ T cells, where the normal proportions of the two major subsets of γδ T cells (designated Vδ1 and Vδ2) become inverted due to a selective depletion of Vδ2 T cells expressing the phosphoantigen-responsive Vγ9 chain (Vγ9Vδ2 T cells) (6). The gene discussed is CD4; the disease is HIV infectious disease.