Given the crucial role of SREBP‐1 induction and subsequent fatty acid metabolism in cancer cell growth, we performed a series of in vitro experiments to elucidate the potential contribution of SREBP‐1 and FASN to leptin‐stimulated growth of breast cancer cells, and clearly demonstrated that SREBP‐1 activation and FASN induction mediates the promoting actions of leptin on cancer cell growth (Fig. 6). This evidence concerns the gene LEP and breast cancer.