The randomized, phase III SOLAR-1 trial of patients with PIK3CA-mutated HR-positive, HER2-negative advanced breast cancer who received prior endocrine therapy showed a longer PFS (HR = 0.65, 95% CI 0.50–0.85, p < 0.001) in patients treated with alpelisib plus fulvestrant compared with fulvestrant alone [110]. The gene discussed is ERBB2; the disease is breast cancer.