IGF1 and cancer: Indeed, the well-documented cancer-preventive effects of caloric restriction are partially attributed to inhibiting the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway through reduced circulating levels of insulin and IGF1, along with increased levels of IGF1-binding protein 1 and 2 (IGFBP-1 and 2) [3].