IGF1 and breast cancer: Dysregulation of the insulin/IGF signaling (IIGFs), involving the overexpression of receptors for IGF-1 and/or insulin (IGF-1R and IR) and/or cognate ligands (IGF-1, IGF-2), has an important role in the early phases of carcinogenesis of breast cancer, and is associated with cancer progression and metastases and resistance to a variety of therapies [1–4].