PML and acute promyelocytic leukemia: Interestingly, we noted significantly elevated steady-state levels of histone acetylation at PML-RARA binding sites in hrAPLs as compared to low/intermediate-risk APL (pt#9) (Figure 2D) in both control and ATRA-treated samples, suggesting that abnormal hyperacetylation at PML-RARA binding sites might be a crucial property of high-risk APLs.