FBXO5 and neoplasm: β-TRCP has previously been shown to function as a tumor suppressor by targeting various oncoproteins such as β-catenin, CDC25A, FBXO5, IκB and DEP domain-containing mTOR-interacting protein (DEPTOR) (Guardavaccaro et al., 2003; Gao et al., 2011; Busino et al., 2003).