Finally, we believe that Kaiso is backed up by an at least partially redundant family member, possibly ZBTB14, accounting for the roughly 50% attenuation of APC-mediated tumorigenesis upon removal of Kaiso alone; in particular, the CML example illustrates a potent synthetic lethal interaction between BCL6 and the activated Abl tyrosine kinase [35]. Here, BCL6 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.