ESR1 and breast carcinoma: Triple negative breast carcinomas (TNBC) were 45.6% (n = 21/46), tumors with ER+/PR+/HER2– (Luminal) were 23.9% (n = 11/46), and only one case (2.2%) expressed both ER and HER2 but negative for PR (Table 12, Fig. 4).