part of part of lobe of prostate Anatomically, the human prostate gland is located between the base of the bladder and the rectum, and it completely surrounds the proximal urethra (Fig. 1A). It is a single alobular structure with central (CZ), peripheral (PZ) and transitional (TZ) zones. In contrast, the mouse prostate is not merged into one compact anatomical structure. It comprises four paired lobes situated circumferentially around the urethra, immediately caudal to the urinary bladder-namely, anterior (AP), dorsal (DP), lateral (LP), and ventral (VP) prostate (Fig. 1B). Often, the dorsal and the lateral lobes are thought of in combination and referred to as the dorsolateral (DLP) lobe as they share a ductal system. The mouse AP is considered analogous to the human CZ, which is rarely a site of neoplastic transformation in humans. The mouse DLP is considered most similar to the human PZ, which is the zone in which most carcinomas arise (Xue et al. 1997). These analogies, however, are limited as they are based solely on descriptive data and need to be re-evaluated using molecular techniques before the relationship between specific mouse prostate lobes and the human prostate zones is definitively asserted (Abate-Shen & Shen 2000). The mouse VP does not have a human homologue, and the human TZ does not have a murine homologue A portion of a prostate that forms a lobe. NCIT:C52726 lobe of prostate gland prostatic lobe SCTID:279692004 prostate gland lobe EMAPA:35712 BTO:0000548 FMA:19570 MA:0001738 UBERON:0001328 UMLS:C0227970 prostate gland reproductive structure anatomical lobe Terry Hayamizu Robert Druzinsky Christopher J. Mungall