BaF3/ITD cells show decreased NHEJ efficiency and increased repair errors compared with parental BaF3 control cells. Relative NHEJ repair efficiency (A) and percentage of DSBs that are misrepaired (B) in BaF3 and BaF3/ITD cells. (C) An agarose gel image of colony PCR products of the region spanning the repaired DSB, using randomly selected white (misrepaired) colonies as templates. The size of a PCR product from a correctly repaired DSB is 628 bp. PCR products of a smaller molecular weight indicate that deletions have occurred during repair. Molecular size markers are indicated on the right. (D-E) Relative repair efficiency (D) and percentage of DSBs that are misrepaired (E) in BaF3/ITD cells treated with the FLT3 inhibitor CEP-701. P values are shown for all graphs. Vertical lines represent SD.