RUNX1 and breast cancer: Interestingly, in this study, additional recurrent abnormalities occurring in breast cancer have been discovered, including mutations of the transcription factor CBFB (core-binding-factor beta subunit), which is associated with hemizygous deletions of one allele of RUNX1 (4% of cases) and homozygous deletions of RUNX1 (about 2% of cases); a balanced translocation between the MAGI3 and the AKT3 genes leads to the formation of the MAGI3-AKT3 fusion protein, exhibiting constitutive activation of the AKT kinase (about 3% of all cases and more frequent in triple-negative breast cancers) [39].