TAC1 and neoplasm: In this regard, we note that the NP-CARN and NPK-CARN mice develop tumor phenotypes similar to those in NP and NPK mice, which have the same genotypes but whose tumors are induced by the Nkx3.1CreERT2 driver in hormonally intact adult prostate (Aytes et al., 2013; Floc'h et al., 2012).