Alpelisib is a molecule primarily developed for the treatment of PIK3CA-mutated cancers: it is a direct and specific inhibitor of the p110α subunit of PI3K, which is strongly and permanently activated due to the presence of a gain-of-function mutation in PIK3CA. Using a selective inhibitor of p110α, which is at the top of the PI3K/AKT/mTOR signaling pathway, it provides a direct outcome on affected tissues while reducing the risk of off-target effects. The gene discussed is MTOR; the disease is cancer.