Transwell migration assay. The functional incorporation of the acquired CCR7 receptors on NK cells was assessed with transwell migration assay. The percentage of migration was assessed by the formula (no. of cells that migrated to the lower chamber/no. of cells seeded in the upper chamber) × 100. The data were acquired by setting up triplicate wells per chemokine condition, and triplicate counts were performed per each well. NK cells obtained from 4 different donors were used in the analysis (n = 4). The statistical significance was assessed with a nonparametric Wilcoxon test, and the data are presented as median ± range.