ESR1 and neoplasm: This difference can be attributed to possible differences in ethnic incidence, as reported previously, and to the overestimation of the true incidence potentially by the use of TMA containing part of the tumor, as we defined TNBC as all negative for ER, PR and HER2, which is similar to known phenomena of the discordance of ER, PR and HER2 expression between samples from core biopsy and excision[22-24].