However, its molecular characterization only came to light between 1982 and 1984 [576,577,578], demonstrating the in-frame juxtaposition of the ABL oncogene (on chromosome 9) with the BCR gene (on chromosome 22), resulting in the hybrid BCR/ABL gene that gives rise to a chimeric protein with high tyrosine kinase activity and with a critical role in the development of leukemia [579]. Here, BCR is linked to leukemia.