Insulin Like Growth Factor-I (IGF-I) is a polypeptide growth factor which stimulates the proliferation of a wide range of cell types including muscle, bone, and cartilage tissue. Insulin-like growth factor 1 (IGF-I) is involved in regulation of neuronal growth and development in central and peripheral nervous system. It is known to protect neurons against cell death induced by amyloidogenic derivatives, glucose or serum deprivation through pathways involving AKT kinase and transcription factor FKHRL1 phosphorylation. Activation of the insulin-like growth factor system has emerged as a key factor for tumor progression and resistance to apoptosis in many cancers like breast and thyroid cancers.