However, in contrast to the above-mentioned substances, with alpelisib a PI3K inhibitor is available for the PIK3CA-mutated, postmenopausal aBC patient, since it shows a statistically significant benefit regarding PFS as well as a meaningful clinical benefit in OS, with an acceptable safety profile at the same time [49,50,51,52]. This evidence concerns the gene PIK3CA and aneurysmal bone cyst.