Because homozygous germline deletion of Pkd1 or Pkd2 in mice lead to embryonic lethality, conditional/kidney-specific knockout, and hypomorphic models are more suitable to investigate ADPKD pathogenesis (Herron et al., 2002; Leeuwen et al., 2004; Piontek et al., 2004; Piontek et al., 2007; Yu et al., 2007; Takakura et al., 2008). Here, PKD2 is linked to autosomal dominant polycystic kidney disease.