Increased ROS levels in FLT3/ITD-positive human AML cell lines and patient samples. (A) Endogenous ROS was measured in 3 human leukemia cell lines: MOLM-14 and MV-4-11 (FLT3/ITD-expressing cells), and REH (FLT3/WT-expressing cell). Shown are the relative ROS levels, of which the MOLM-14 was set at 100%. REH cells exhibited a significantly lower ROS level than both MOLM-14 and MV-4-11. (B) MOLM-14 and MV-4-11 cells exhibit greater reduction in ROSs than REH cells, following CEP-701 treatment. (C) Patient samples with FLT3/ITD (n = 3) and without FLT3/ITD (n = 3) were analyzed for ROS levels, and FLT3/ITD-bearing samples were also treated with CEP-701. FLT/ITD cells exhibited significantly higher ROS, which was decreased after CEP-701 treatment. The error bars represent plus or minus SEM.