In those studies, we used a mouse monoclonal antibody directed against recombinant human ERα; the epitope for this antibody was not defined, but it recognised a protein of 66 kDa (consistent with full-length wild-type ERα) in breast cancer cell homogenates detected by western blot (Chantalat et al., 2016) and detected ERα in both stromal and epithelial cells by immunohistochemistry (Bombail et al., 2008). This evidence concerns the gene ESR1 and breast carcinoma.