Eight members of this class of 120 TP53-MW genes encode protein kinases: AURKA, BUB1, BUB1B, CDK1, MELK, NEK2, PLK1 and TTK. The products of these eight genes are of particular interest as targets for the development of small-molecule kinase inhibitors, a strategy adopted by several cancer therapies [18]. Here, PLK1 is linked to cancer.