We show that knockout of Usp47 significantly prevents BCR-ABL or BCR-ABLT315I-induced leukemogenesis and reduces the number of GFP+LSK cells in CML mice, indicating that Usp47 is critical in the development of BCR-ABL-induced CML. The gene discussed is ABL1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.