Besides ODC, five other proteins that are upregulated in cancers have been identified as Az1 substrates to date, including DNp73 (encoded by TP73), Aurora A (AURKA), cyclin D1 (CCND1), Mps1 and Smad1 (Lim and Gopalan, 2007; Newman et al., 2004; Kasbek et al., 2010; Gruendler et al., 2001; Dulloo et al., 2010). Here, CCND1 is linked to cancer.