Since the ABL gene expresses a membraneassociatedtyrosine kinase protein, the BCR-ABLtranscript is also translated into a tyrosine kinase.Although the activity of this enzyme is typicallycontrolled by other molecules, the mutant tyrosinekinase encoded by the BCR-ABL transcript resultsin a protein that is "always on" or constitutionallyexpressed, resulting in unregulated cell division(i.e. cancer). The gene discussed is BCR; the disease is cancer.