Chronic myeloid leukemia (CML), also known as chronic myelogenous leukemia, is a clonal hematopoietic stem cell disorder characterized by the translocation of the ABL1 gene on chromosome 9 and the BCR gene on chromosome 22, forming the BCR-ABL1 fusion gene. This evidence concerns the gene BCR and chronic myelogenous leukemia, BCR-ABL1 positive.