This finding indicates that in addition to having a higher infection frequency of proviruses with an intact p24 gene, PD-1+ cells also have a higher proportion of proviruses with intact p24 compared to cells expressing CTLA-4 (both single-positive and DP), which may explain why PD-1+ cells are able to express high levels of p24 protein upon ex vivo stimulation. The gene discussed is PDCD1; the disease is infection.