PIK3CA and neoplasm: These alterations include mutations and/or amplifications of one of the genes encoding one of the four catalytic subunits (PI3Kα, PI3Kβ, PI3Kγ, and PI3Kδ).9,10 The PIK3CA alterations induce a transformed phenotype resulting in independent cell growth and therapy resistance.9,10 Although alpelisib is now only registered and approved for HR+/HER2-negative PIK3CA-mutated metastatic breast cancer, the prevalence of actionable PIK3CA mutations in various tumor types offers the potential to be used in many more patients, beyond its registration and approval label.