NR4A1 and breast cancer: IGF1R-alpha is the main receptor subunit that is able to activate both pERK- and pAkt-mediated downstream signaling pathways [13] and has been implicated in breast carcinogenesis [34], miRNA regulation in HR positive breast cancer cell lines [35] endocrine resistance [36] and aromatase inhibitor-related symptoms [37], suggesting a cross-talk of the IGF receptor with hormone receptors.