For HR‐positive/HER2‐negative advanced breast cancer patients with PIK3CA mutation who had received CDK4/6 inhibitor treatment, it is proved by the BYLieve study [33] for the first time that they can benefit from alpelisib treatment in combination with aromatiase inhibitors (AI), with the efficacy and safety profile unaffected by alpelisib. The gene discussed is CDK4; the disease is breast cancer.