IGF1R and breast cancer: To determine IGF1R-mediated oncogenic roles of GASP1 in breast cancer cells, we ectopically expressed IGF1R in GASP1 knockout HCC1937 and MCF7 cells and found that GASP1 depletion suppressed cell proliferation compared with the control, while IGF1R overexpression could attenuate this effect (Fig. 6a).