PTEN and neoplasm: To model this in vivo, genetically engineered mouse models of prostate cancer with prostate specific Pten homozygous deletion harboring either a KRasG12D activating mutation or oncogenic BRafV600E with NK3 Homeobox 1 (Nkx3.1) depletion, promotes rapid tumor growth and metastatic progression relative to the single mutants [101,268,269].