The capacity of anti-FASN therapy to restore the sensitivity to tamoxifen and fulvestrant in MCF-7/HRG xenograft tumors certainly suggests that certain subgroups of HRG-overexpressing, ER-positive/HER2-negative patients who phenotypically behave as triple-negative breast carcinomas and are resistant to endocrine therapy could greatly benefit from adding clinical-grade FASN inhibitors [31,32,33] to combined treatments with SERMs/SERDs. This evidence concerns the gene ESR1 and triple-negative breast carcinoma.