Chronic myelogenous leukemia (CML), a type of blood-cell cancer, usually results from a chromosomal aberration whereby a segment of chromosomal DNA containing the gene ABL is inserted within the gene BCR. This creates a chimeric protein named BCR-ABL whose growth-promoting activity cannot be regulated by the normal regulatory mechanisms within the cell. Chimeric proteins such as BCR-ABL can be created by a mutation. translocation point inversion deletion deamination