Chemokine receptor distribution on the cell surfaces of healthy donor–derived NK-cell subsets. Unactivated peripheral NK cells and CANK cell lines were generated and quadruple stained, as described in “Materials and methods.” (A) Chemokine receptor expression on healthy donor CD16⁺ and CD16⁻ unactivated NK and CANK cells. (B-C) Representative chemokine receptor expression values on unactivated NK and CANK cells based on their CD16 phenotype. Indicated values represent the percentage of cells of the total cell population positive for a certain chemokine receptor. (D-G) Time-dependent changes in chemokine receptor expression on NK cells stimulated with 50 U/mL IL-2 in comparison with CANK cells. (D) CXCR3 changes on CD16⁺ NK. (E) CXCR4 changes on CD16⁻ NK. (F) CCR2 changes on polyclonal NK. (G) CX3CR1 changes on CD16⁺ NK. Values indicate mean fluorescence intensity (MFI) values for each staining. (H) Migration assay for healthy donor polyclonal unactivated NK (light gray) and CANK cell lines (dark gray) to multiple chemokines at optimal concentration levels was performed, as described in “Materials and methods.” Matching receptor and concentration used for each chemokine are indicated in brackets. Results are from 1 representative experiment of 3 to 23 experiments performed.