MTOR and neoplasm: However, the BOLERO‐2 study which examined the benefit of an inhibitor of the PI3K/AKT/mTOR pathway (everolimus), has shown a benefit for patients when everolimus was added to endocrine therapy regardless of the presence of a PIK3CA mutation (H1047R, E545K, and E542K) in either tumor tissues or ctDNA samples analyzed by droplet digital PCR (ddPCR), suggesting that PIK3CA mutation status is not a predictive determinant for everolimus benefit (Moynahan et al., 2017).