ESR1 and breast cancer: The Insulin-like growth factor receptor (IGF-1R), is highly expressed in breast cancers, such as estrogen receptor positive (ER+) and triple negative (TNBC) and its expression is associated with a worse clinical prognosis [18, 19] Upon dimerization and activation by IGF-1, IGF-1R activates many downstream signaling cascades including the Akt-mTORC1 pathway that controls many metabolic processes [20].