We observed that knockdown of Gi1/2/3 not only clearly reduced the growth rate of breast cancer cells (Figures 4A and 4B, Additional file 3: Figure S3), but also significantly diminished their invasion ability in response to EGF, bFGF, IGF-1 and FBS (Figures 4C and 4D). This evidence concerns the gene IGF1 and breast carcinoma.