To assess and describe patient-reported outcomes (PROs) in women with locally advanced/unresectable or metastatic breast cancer (aBC/mBC) with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR + /HER2 −) status receiving palbociclib combination therapy in a US real-world setting. The gene discussed is NR4A1; the disease is aneurysmal bone cyst.