BCR and chronic myelogenous leukemia, BCR-ABL1 positive: In a case where CLL followed CML six years after its diagnosis, the genomic studies suggested separate origins for myeloid and lymphoid clones which carried mutually exclusive positive genomic markers (del17q11 (CLL) and BCR/ABL (CML), supporting the two genomic events/two diseases hypothesis (D’Arena et al., 2012).