As previously described [56], the percentage of human CD4+ cells decreased in vehicle- (17.7 to 11.4%) or D1143-treated mice (17.2 to 10.8%) likely due to the HIV-1 infection-mediated depletion of human CD4+ cells while the percentage of human CD4+ cells slightly increases in anti-PD-1- (17.7 to 19.2%) and anti-PD-1/D1143-treated mice (18.1 to 20.2%). Here, CD4 is linked to HIV-1 infection.