Detection of in vivo elevated levels of CD4^dimCD8^bright T cells in HIV+ patients. Increased CD4^dimCD8^bright T cells were detected among 6 HIV⁺ patients (A-F), and the percent of dual CD4 and CD8 expression is indicated in the upper right quadrant. Patient 1 represents an antiretroviral-naive patient who was monitored at baseline, week 12, and week 24 after treatment. The percent expression of CD4^dimCD8^bright T cells in patient 6 is shown by gating on total CD3⁺ T lymphocytes or on CD3⁺CD8⁺ lymphocytes.