BTK and pneumonitis: Third, all patients included for the efficacy analysis carried alterations in PI3K/ATK/mTOR pathway, which were reported to be associated with poor prognosis as indicated by IMPACT study.7 Besides, the incidences of pneumonitis and grade 3‐5 hematological adverse events in the everolimus group were relatively lower in the studied cohort as compared to the previous reports,34, 35 which may due to the heavily treated MBC patients with active alterations in PI3K/ATK/mTOR pathway in our study and the fact that everolimus was used outside its indications.