CXCL8 favors NK cell differentiation. UCB CD34⁺ cells were purified and cultured in the presence of cytokine-mix. At day 12 of culture anti-CXCL8 and anti-CCL3 blocking antibodies were added to the culture alone or in combination. Cells were further cultured for 5 days and then analyzed for the expression of CD56, CD161, CD33, and CD14. (A) Flow cytometric analysis for the surface expression of the indicated markers. Representative experiments of 8 performed. (B) Statistical analysis of the effect of anti-CXCL8 and anti-CCL3 neutralizing mAbs on NK and monocyte cell differentiation. Data are expressed as median values of fold increase/decrease of percentages of cell positive for the indicated surface markers versus control (arbitrarily normalized to 1) obtained in 8 independent experiments. Data were analyzed by Wilcoxon signed rank test (**P ≤ .001; *P ≤ .05).