SKP2 and osteosarcoma: Similarly, in osteosarcoma, Cx43 CT inhibited cell proliferation by downregulation of S phase kinase-associated protein 2 (skp2) expression, an important component of the Skp1-Cullin-F-box protein (SCF) ubiquitin–ligase complex implicated in p27 ubiquitin–proteasome degradation [111].