AR agonists, such as the natural ligand dihydrotestosterone (DHT) or the Selective Androgen Receptor Modulator (SARM) enobosarm (lacking virilising activity), exert an anti-proliferative effect in normal mammary epithelium, as well as in ERα+ breast cancer, both in vitro and in vivo [18,19,20,21,22,23,24,25,26]. This evidence concerns the gene ESR1 and breast cancer.