Schematic diagram illustrating potential patterns of human prostate cancer development and the neoplastic prostate growth in LADY mouse. A, Human prostate cancer originates from prostate epithelial cells; either basal cells or luminal cells [51–53]. Although primary prostate cancer is regarded as multifocal, advanced prostate cancer is postulated to be monoclonal . Cancer associated stromal cells proliferate in the oncogenic processes . B, In the LADY-mouse prostate, ubiquitously expressed T-antigen oncogene enables various types of cells, including stromal cells, to be hyper-proliferative and oncogenic in multiple regions. As the results, cancer could originate from multiple types of progenitor cells.