Western blot analysis of extracts from COS cells, treated with λ phosphatase or 20% FBS as indicated, using Non-phospho-4E-BP1 (Thr46) (87D12) Rabbit mAb (upper), Phospho-4E-BP1 (Thr37/46) Antibody #9459 (middle), and 4E-BP1 Antibody #9452 (lower).