An example would be imatinib mesylate (Gleevec, Novartis) that targets the Philadelphia chromosome (BCR-ABL fusion) protein in chronic myeloid leukemia (CML) patients, competitively binding to its Adenosine triphosphate (ATP) domain and disrupting the tyrosine kinase activity (2). Here, BCR is linked to chronic myelogenous leukemia, BCR-ABL1 positive.