The randomized, phase III clinical trial SOLAR-1 provided evidence that treatment with Alpelisib-fluvestrant prolonged progression-free survival among patients with PIK3CA-mutated, HR-positive, HER2-negative advanced breast cancer who had received endocrine therapy previously (in the Alpelisib-fulvestrant group the PFS was 11 months as compared to 5.7 months in the placebo group) [315]. Here, ERBB2 is linked to breast cancer.