A comparison of VPA sensitivity in human AML cell lines demonstrated that two cell lines harboring mutated UTX (utx-1), namely THP-1 and MONO-MAC-1, were significantly less sensitive to VPA-induced cell death (Figure 5B and C), revealing UTX as a sensitizer of VPA toxicity also in human AML cells. The gene discussed is KDM6A; the disease is acute myeloid leukemia.