PLK1 and neoplasm: Overall, cluster C6 genes (that is, genes with greater up-regulation in tumors from ApcMin/+ and AOM models than in Smad3-/- and Tgfb1-/-; Rag2-/-) were consistent with increased tumor cell proliferation (for example, Myc, Pcna), cytokinesis (for example, Amot, Cxcl5), chromatin remodeling (for example, Ets2, Hdac2, Set) as well as cell cycle progression and mitosis (for example, Cdk1, Cdk4, Cul1, Plk1).