BCR and chronic myelogenous leukemia, BCR-ABL1 positive: This reciprocal translocation, creatingan elongated chromosome 9 der(9) and a truncatedchromosome 22 (Ph chromosome), is the hallmarkof CML and the main drugs which target this oncogenicfusion gene (BCR-ABL) are imatinib and sunitinib.The protein encoded by the fusion gene exhibitsenhanced tyrosine kinase activity and plays akey role in the initiation and maintenance of CML byactivating various intracellular signalling pathwaysresulting in uncontrolled proliferation, decreased apoptosisand survival of leukemic stem cells (4).