Previous FISH studies rarely detected AR gene amplification in clinically localized prostate tumors before hormonal therapy, but gain of the X-chromosome has been reported in 30–50% patients when a cutoff for gain was set at 9.8% of all cells examined [30], [31], which implied that an average of > = 1.1 copies of the X-chromosome per nucleus were considered abnormal. This evidence concerns the gene AR and prostate neoplasm.