AR and prostate carcinoma: The results of our evaluation of xenograft models provide additional supporting evidence of the androgen-negative regulation of SRD5A3. Because we did not use castrate xenograft models and thus could not directly compare the effect of androgen withdrawal on the AR-positive and -negative cells in vivo, we did observe SRD5A3 overexpression in the AR-negative prostate carcinoma xenografts MDA PCa 144 and MDA PCa 146, which is consistent with results from our cell line study and previously reported work [10], [11].