Furthermore, and further attesting to the relevance of identifying actionable PIK3CA mutations in breast cancer, major hot spot-activating missense PIK3CA mutations (E542K, E545K/A, H1047R/L) have a level IA of evidence for actionability according to the ESMO Scale for Clinical Actionability of molecular Targets (ESCAT; (Condorelli et al., 2019). The gene discussed is PIK3CA; the disease is breast cancer.