The eligibility criteria were as follows: age ≥18 years; histologically confirmed hormone receptor-positive, HER2-negative breast cancer; recurrent or metastatic disease; at least one measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1; and no prior systemic endocrine therapy for advanced disease. The gene discussed is NR4A1; the disease is breast cancer.