A recent analysis of 649 mBC patients from SAFIR02 trial (NCT02299999) found that, in HR+/HER2− mBC, PIK3CA mutations are associated with poor overall survival (OS) and resistance to chemotherapy [24], as well as in HER2+ metastatic BC, wherein PIK3CA mutations are associated with poor outcomes and resistance to HER2-targeted therapy [25]. The gene discussed is ERBB2; the disease is breast cancer.