In vitro flow cytometry apoptosis analysis shows an additive effect of treatment with pazopanib and cytarabine. (A) KG-1 cells exposed to pazopanib and cytarabine demonstrate modest reduction in viability by XTT assay. In combination, the effect is additive, significantly decreasing viability of AML cells relative to controls. *p-values <0.05 for all treatment samples, compared to untreated control. (B) In the presence of an EC feeder layer, the addictive effect of pazopanib and cytarabine on AML cells persists. *p-values <0.05 for all treatment samples, compared to untreated control. (C) Western blot of phosphorylated SRC, a downstream target of RTK signaling, shows a dose-dependent decrease in phosphorylation with pazopanib exposure.