PKD2 and Kidney Cyst: Development of PKD-type kidney cysts was apparent in all (10/10) of the induced cPkd2 mice after one year, whereas none of the Pkd2+/+ (0/18), Pkd2+/del-Z (0/19) and Pkd2del-Z/del-Z (0/18) animals developed PKD-type cysts.