To assess if MTAP expression was lost or changed during the process of CaP recurrence after androgen deprivation therapy (ADT), RNA was isolated from 6 samples of benign prostatic hyperplasia (BPH), 7 samples of androgen stimulated CaP (AS-CaP), and 4 samples of ADT-recurrent CaP (ADT-RCaP). Here, MTAP is linked to benign prostatic hyperplasia.