Gene expression array in culture-derived MKs. (A) Enrichment of the “chemokine activity” gene set in Nbeal2^−/− MKs with the genes contributing to this enrichment. (B) Fold change of the 6 most significant genes identified in (A) in Nbeal2^−/− vs control MKs generated by qPCR using different samples as those used in the array (n = 3). (C) Plasma levels of the chemokines MIP-1α (Ccl3), MIP-1β (Ccl4), and Cxcl1 in MK culture supernatant. (D) Levels of these chemokines in plasma of control and Nbeal2^−/− mice (n = 5). Bars represent mean ± standard error of the mean. *P < .05.