CD4 and HIV infectious disease: In summary, the manual analysis results showed that activation (CD4+CD38+HLA-DR+, CD4+HLA-DR+) and exhaustion (CD4+PD-1+) markers were primarily correlated with the laboratory parameters, whereas the results from the FLOCK analyses showed that it was specific activation and exhaustion profiles of early-differentiated memory clusters that were linked to the immunopathogenesis of HIV infection.