A. MEDI-573 inhibits bot IGF-1 and IGF-2 stimulation of Akt phosphorylation. Sarcoma cells were grown for 24 hr under serum-free conditions, then incubated for 5 - 60 min with MEDI-573 (30μg/ml), or 5 min without antibody, and stimulated for 5 min with IGF-1 (10 ng/ml) or IGF-2 (50 ng/ml). B. MAB391 inhibits only IGF-1 not IGF-2 stimulation of Akt phosphorylation. Sarcoma cells were grown for 24 hr under serum-free conditions, then incubated for 5 - 60 min with MAB391 (15μg/ml), or 5 min without antibody, and stimulated for 5 min with IGF-1 (10 ng/ml) or IGF-2 (50 ng/ml). Cells were harvested 5 min after IGF-stimulation at the times shown and phosphorylation of Akt(Ser473) and total Akt determined by immunoblotting.