ESR1 and breast neoplasm: It is possible that BLBCs are more effectively identified by gene expression profiling than by immunohistochemical selection of tumors negative for ER/PR/HER2 and positive for CK5/6, CK14 or EGFR, as done by Manie et al. Of note, the TP53 mutation analyses for the BRCA1-mutated breast tumors and the BLBCs described in this manuscript were performed in different labs, thereby reducing the possibility that the detection of a high incidence of complex/truncating TP53 mutations is due to a methodical artifact.