CDC20 and cancer: Several CIN-associated genes were strongly upregulated, including the spindle assembly checkpoint machinery genes AURKA, AURKB, BUB1, BUB1B and MAD2L1;27, 28 regulators of sister chromatid segregation PTTG1 and ESPL1;29 and CDC20, a subunit of the anaphase-promoting complex/cyclosome, which is overexpressed in several human cancers and associated with poor prognosis30 (Figure 2a, Supplementary Table S1).