Amongst the 69 F-box proteins, only four members—FBXW7, SKP2, β-TrCP1, and β-TrCP2—have been extensively studied, and 15 of them are so far identified to play determined roles in cancers and they are grouped into four categories: tumor suppressive, oncogenic, context-dependent, or undetermined functions in cancer [4]. Here, SKP2 is linked to cancer.