CDC20 and cancer: We conclude that Cdc20-derived peptides, the Tyc1 protein, and the human-derived hp31 peptide can serve as novel molecular tools to explore mechanisms for inhibiting the APC/C that give rise to a sensitivity to microtubule poison in vivo as a strategy for moving towards a long-term goal of targeting cancer cells that have been treated with a microtubule poison but under-go ‘mitotic slippage’ [1–12].