Expression of CCR6 and CCR7 in CD4⁺ or CD8⁺ CD45RA⁻ T cells in healthy and HIV-infected individuals. Results are expressed as a percentage of CD4⁺ (upper panel) and CD8⁺ (lower panel) CD45RA⁻ T cells that do or do not express CCR6 coexpressed with CCR7; □, healthy individuals; ▪, HIV-infected patients. *P < .05; **P < .01. Error bars represent SEM.