Like β-TrCP1, SKP2, another well-characterized F-box protein, acts as a classic oncogene which promotes proliferation and survival of cancer cells, mainly through targeted degradation of a number of tumour suppressive proteins, including p21 (ref. 34), p27 (refs 35, 36), p57 (ref. 37), p130 (ref. 38), FOXO1 (ref. 39), among many others40. This evidence concerns the gene FOXO1 and neoplasm.