Although CD73+ CD4+ T cells had a resting phenotype of very low CD38 and Ki-67 expression and high Bcl-2, suggesting reduced in vivo proliferation, which could mean potentially reduced permissiveness to HIV-1 infection, we have consistently found that resting CD127high CD4+ T cell subsets contain HIV DNA [41,50,51,52]. Here, CD38 is linked to HIV-1 infection.