In advanced breast cancer, the alpha-specific PI3-Kinase (PI3Kα) inhibitor alpelisib, in combination with endocrine therapy (fulvestrant), showed promising results in HR+ HER2− breast cancer with PIK3CA mutations, with a doubling in the median PFS (11.0 vs 5.7 months), as reported in the phase III SOLAR-1 trial [32]. The gene discussed is ERBB2; the disease is breast cancer.