CCR7^loCXCR3^hi CD8⁺ T cells display an effector phenotype. (A) PBMCs from healthy human blood were stained for surface receptors CD8, CD45RA, CXCR3, CCR7, and intracellular perforin and granzyme B. Four individual donors were used in replicate experiments, and representative plots from one experiment are shown. (B) Healthy human PBMCs were stained with antibodies specific for CD8, CCR7, and CXCR3 and sorted into 3 separate CD8⁺ populations as indicated in the figure. Redirected lysis assay was carried out at the indicated E:T ratios using anti–human anti-CD3–coated THP-1 target cells. The result was repeated with cells isolated from 2 healthy donor samples with similar results.