PDCD4 and neoplasm: β-TrCP1 (β-transducin repeat-containing protein 1), one of the prototypical and best characterized mammalian F-box proteins, exerts oncogenic functions in most cases by promoting targeted degradation of many tumour suppressors, including p53 (ref. 22), Bim EL (ref. 23), procaspase-3 (ref. 24), IκB (ref. 25), programmed cell death protein 4 (PDCD4) (ref. 26) and DEPTOR (refs 27, 28, 29).