XRCC6 and acute myeloid leukemia: Consistent with the results obtained using FLT3-ITD mutant AML cells, AIU2001 treatment reduced the mRNA levels of the HR (BRCA1, BRCA2, BARD1, and RAD51) and NHEJ (XRCC5 and XRCC6) machineries in A549 and H1299 cells (Figure 5A).