SKI and neoplasm: Inhibition of autocrine TGF-β signaling by stable overexpression of SMAD7 in the 1205Lu cell line did not significantly alter SKI protein content, yet dramatically inhibited MatrigelTM invasion, and almost entirely blocked subcutaneous tumor growth and the appearance of experimental bone metastases in mice (Table 2), Together, these results suggest uncoupling of the pro-invasive and pro-metastatic activities of TGF-β with SKI protein levels in melanoma cells, or at least indicate that SKI function is relatively marginal as compared to the tumor promoter activities of TGF-β