ORR was similar with aromatase inhibitors (giredestrant + palbociclib: 50%, 95% CI; AI + palbociclib: 49%, 95% CI) (CoopERA Results Show Benefits of Giredestrant in ER+/HER2– Early Breast Cancer, 2023; Fasching et al., 2022). Here, CYP19A1 is linked to breast cancer.