This translocation fuses the breakpoint cluster region (Bcr) and the Abelson kinase (Abl) genes, forming the Bcr-Abl oncogene that encodes the constitutively active cytoplasmatic tyrosine kinase (TK) Bcr-Abl [2,3], present in >90% of CML cases. Here, BCR is linked to chronic myelogenous leukemia, BCR-ABL1 positive.