AR was mostly expressed in the nucleus of MDA-MB-453, whereas, in MDA-MB-468 or MCF-7, it was mostly expressed in the cytoplasm; also, ERβ was mostly expressed in the cytoplasm and cytoplasmic membrane, according to Shaaban et al. (2008), who stated that, in breast cancer, ERβ expression in the cytoplasm is more abundant than in the nucleus [49]. The gene discussed is ESR2; the disease is breast cancer.