KRAS and neoplasm: Murine PCSCs generated as a result of expressing constitutively-active Kras(G12D) (PBCreKrasG12D/+) or deleting Pten (PBCrePtenlox/lox) in prostate epithelial cells initiated orthotopic tumor formation, while neither PCSC population was capable of generating detectable macrometastases by 10 weeks post-transplantation.