Ruxolitinib inhibits proliferation of AML cells. (A) Cell proliferation analysis by FACS using BD bromodeoxyuridine (BrdU) flow assay. Left, representative plots; right quantification for different AML cell lines treated with 2 µM ruxolitinib or vehicle for 2 days (n = 3-6). (B) Quantification of apoptotic cells by Annexin V assay in different AML cell lines after treatment with 2 µM ruxolitinib or vehicle for 3 days (n = 3-6). Data are shown as mean ± SEM. See also supplemental Figure 3.  *P < .05; **P < .01; ***P < .001; ****P < .0001 as determined by Student t test. n.s., not significant.