Determining the source of regenerated luminal epithelial cells in the adult prostate during androgen deprivation and replacement will provide insights into the origin of prostate cancer cells and their fate during androgen deprivation therapy. Prostate stem cells in the epithelial layer have been suggested to give rise to luminal epithelium. However, the extent of stem cell participation to prostate regrowth is not clear. In this report, using prostate-specific antigen-CreER(T2)-based genetic lineage marking/tracing in mice, preexisting luminal epithelial cells were shown to be a source of regenerated luminal epithelial cells in the adult prostate. Prostatic luminal epithelial cells could survive androgen deprivation and were capable of proliferating upon androgen replacement. Prostate cancer cells, typically exhibiting a luminal epithelial phenotype, may retain this intrinsic capability to survive and regenerate in response to changes in androgen signaling, providing part of the mechanism for the ultimate failure of androgen deprivation therapy in prostate cancer.