Capivasertib, an AKT inhibitor, approved in combination with fulvestrant for hormone receptor–positive, human epidermal growth factor receptor 2–negative advanced breast cancer with ≥1 PIK3CA, AKT1, and/or PTEN alterations, significantly improved progression-free survival in the CAPItello-291 phase 3 trial. Here, AKT1 is linked to breast cancer.