ESR1 and Familial prostate cancer: Two breast cancer cell lines, MCF-7 (ER- and AR-responsive) [66,68] and MDA-MB-231 (mostly reported as ER- and AR-non-responsive) [66,69]; two prostate cancer cell lines, PC-3 (AR-non-responsive and ER-responsive) [70,71] and LNCaP (AR-responsive and ER-non-responsive) [72]; and human primary dermal fibroblasts were selected, the latter serving as a hormone-independent cell line for control purposes (Figure S1).