PDCD1 and HIV infectious disease: HIV infection was linked to an increase in the frequencies of PD-1+ FoxP3+ CD8 T-cells (p< 0.0001 for both acute and chronic ART-) and CTLA-4+ FoxP3+ CD8 T-cells (p< 0.0001, p= 0.003 for acute and chronic ART-, respectively) compared to uninfected individuals (Figures 3C, D).