Among them, abemaciclib showed statistically significant and clinically meaningful improvements in progression-free survival (PFS) and overall survival (OS) while maintaining the health-related quality of life (HRQoL), both when given with fulvestrant in endocrine-resistant aBC and when given with a non-steroidal aromatase inhibitor (AI) in endocrine-sensitive aBC. The gene discussed is CYP19A1; the disease is aneurysmal bone cyst.