Interestingly, UTX is highly frequently mutated in human blood malignancies and solid cancers.15–20 For example, UTX is mutated in approximately 10% chronic myelomonocytic leukemia (CMML) and CMML-derived acute myeloid leukemia (AML) patients and 20% acute lymphoblastic leukemia (ALL) patients.5,14,21UTX is essential for multiple biological processes including stem cell self-renewal, embryogenesis, and posterior development.22–25 In cancer biology, UTX is considered as a tumor suppressor gene of various cancers. The gene discussed is KDM6A; the disease is cancer.