Regardless of its relatively small size,the prostate is the most common site of pathology in human male,1,2 and the prostate is the site of the two most frequent medical problems affecting elderly men,benign prostatic hyperplasia (BPH) and prostate cancer (PCa).Using the urethra as the key anatomical reference point,the prostate is conventionally divided into three distinct zones:peripheral zone,transition zone,and central zone.2This morphology is of clinical significance in the development of age-associated conditions such as BPH and PCa.3 Each of these zones exhibit a specific susceptibility to pathology,PCa develops mainly in the peripheral zone,whereas BPH occurs almost exclusively in the transition zone,whilst the central zone remains mostly disease-free.2,4,5 The functional basis and molecular mechanisms underlying these differences in disease susceptibility between the zones of the human prostate are unknown.Some of the differences in susceptibility to disease may have an embryological basis.