SKP2 and cancer: Skp2 has been reported to be up-regulated in a large number of human cancers, including prostate cancer, breast cancer, lung cancer, colorectal carcinoma, liver cancer and others [19].The Skp2-containning SCF (SCFSkp2) has been previously reported to participate in proteasomal degradation of cyclin-dependent kinase inhibitors (CDKIs) that are key regulators of cell cycle [20].