BUB1 and breast cancer: These proteins make up three groups: 1) the c-Myc and c-Myb transcription factors, which are expressed in a great variety of tumors [49]–[52], 2) the DNA repair and recombination proteins BRCA1 and 2, which are amplified in breast cancer and non-small-cell lung cancer [53], [54], and 3) the proteins assigned to mitotic checkpoints, such as BUB1 and BUB3, which can result in genomic instability when overexpressed [55], [56].