ESR1 and breast cancer: In the histological examination of receptors and proteins encoded by these response genes, immunohistochemistry has revealed relationships between ER and pS2/pNR-2/TFF1 in breast cancer (Henry et al. 1991, Koerner et al. 1992, Suzuki et al. 2004) and between AR and prostate-specific antigen in prostate cancer (Zhang et al. 1998, Ogreid et al. 1999).