UTX is an important epigenetic regulator, and many human cancers harbor mutations or deletions in this gene.2 A series of recent studies have established the role of UTX as a tumor suppressor in leukemia, lymphoma, pancreatic, and lung cancers.3–7 In particular, it was also demonstrated that UTX escapes from X chromosome inactivation, therefore females have more functional copies of this tumor suppressor than do males, and different dosages of UTX in male and females contribute to cancer sex bias.5,8. The gene discussed is KDM6A; the disease is leukemia.