Unlike tumor suppressive E3 ligase such as FBW7 and FBXO4, or oncogenic E3 ligase such as SKP2, β-TRCP (β-TRCP1 and β-TRCP2) displays context-dependent (tumor type or cellular context) functions in tumorigenesis (Wang et al., 2014; Skowyra et al., 1997). The gene discussed is FBXO4; the disease is neoplasm.