BUB1B and mosaic variegated aneuploidy syndrome 1: BUBR1 mutations have been identified in various human malignancies, including gastrointestinal cancers [11]–[14], and in a rare human hereditary condition called mosaic variegated aneuploidy (MVA) syndrome, in which high rates of chromosome missegregation lead to systemic aneuploidy, typically involving more than 25% of cells [15], [16].