NR4A1 and breast carcinoma: Women diagnosed with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) breast cancer are typically treated with endocrine therapy (ET), but intrinsic and acquired ET resistance are common issues in patients with advanced or metastatic breast cancer [2, 3].The cyclin D pathway is an important target for overcoming mechanisms of ET resistance [4].