Recognizes a protein of 110kDa which is identified as androgen receptor (AR). It reacts with full length and the newly described A form of the receptor. It does not cross react with estrogen, progesterone, or glucocorticoid receptors. The expression of AR is reportedly inversely correlated with histologic grade i.e. well differentiated prostate tumors show higher expression than the poorly differentiated tumors. In prostate cancer, AR has been proposed as a marker of hormone-responsiveness and thus it may be useful in identifying patients likely to benefit from anti-androgen therapy. This antibody is superb for staining of formalin/paraffin tissues.