Primary epidermis instructs CCR8 expression by naive T cells. Naive T cells were stimulated with αCD3/CD28 beads for 6 days alone or in the presence of increasing concentrations of epidermal supernatants. The percentages of CD4⁺ and CD8⁺ T cells expressing CCR8 (left) and CXCR3 (right) after 6 days are plotted as mean ± SEM (n = 6) from 3 independent experiments. *P < .05. **P < .01.