SKP2 and cancer: Additionally, SKP2 (SCFSKP2), the F-box protein required for S-phase entry, is overexpressed in numerous cancers including breast [63], Kaposi’s sarcoma [64], T-cell lymphoma [65], and melanoma [66], with increasing SKP2 expression correlating with diminished P27 (CKI) expression, advanced cancer progression, and poor patient prognosis [63,64,65,66].