A fasting-mimicking diet enhances the anti-cancer efficacy of the endocrine therapeutics including tamoxifen and fulvestrant and delays endocrine resistance by lowering circulating IGF1, insulin, and leptin and by inhibiting AKT–mTOR signaling via upregulation of EGR1 and PTEN in mouse models of hormone-receptor-positive breast cancer [110]. This evidence concerns the gene IGF1 and cancer.