Nevertheless, mucosal Vδ2 T-cells were found able to spontaneously produce IFN-γ in HD as well as in primary HIV infection, but this capability was lost in chronic HIV, suggesting a functional exhaustion mechanism during the chronic phase of HIV infection, similarly to other mucosal cells such as CD8 T-cells [36], CD4 T-cells [34], NK cells [37], B cells [38], and Dendritic cells [39]. This evidence concerns the gene CD4 and Huntington disease.