QK041 Recombinant human bovine porcine IGF 1 LR3 protein Insulin like growth factor 1 promotes cell cycle progression via upregulation of cyclin D1 expression through the phosphatidylinositol 3 kinase nuclear factor B signaling pathway in FRTL thyroid cells Acta Pharmacologica Sinica IGF1 LR3 insulin like growth factor IGF 1 LR3 does not promote growth in late gestation growth restricted fetal sheep American Journal of Physiology Endocrinology and Metabolism American Physiological Society Insulin like growth factor 1 stimulates retinal cell proliferation via activation of multiple signaling pathways ScienceDirect