PD-1 blockade reprograms both innate and adaptive immunity in people living with HIV and cancer. It induces interferon-driven antiviral responses that reduce the HIV reservoir. Preexisting type I interferon signature predicts decline in HIV reservoir. High TGFβ signaling, on the other hand, opposes the decrease of the reservoir. These factors define the immune conditions influencing the outcome of PD-1 treatment. The study was published in Nature Medicine on February 12, 2026.