IGF1 and neoplasm: Rapamycin eliminated osteoclastic CM or recombinant IGF-1 induced phosphorylation of S6 in 5-8F, 5-8F OE and BM3 tumor cells (Fig. 5a), and when mTORC1 was inhibited, osteoclastic CM or recombinant IGF-1 failed to promote proliferation of 5-8F OE, and BM3 tumor cells (Fig. 5b).