CD155 expression on CD4 T cells was inversely with CD4 T-cell counts in acute HIV-1 infection (Supplementary Figure 1C, r = −0.53, P = 0.0017) including the first, third month of infection, and in chronic HIV-1 infection (Supplementary Figure 1D, r = −0.54, P = 0.0004) including the twelfth month, over 2 years of infection. Here, CD4 is linked to HIV-1 infection.