PKD1 and autosomal dominant polycystic kidney disease: We crossed the previously characterized Pkd1fl/fl;Pkhd1-Cre (Pkhd1-Cre;Pkd1-KO)22–24,41 ADPKD mouse model, generated on a C57BL/6J background, with N-Pkd1-KO + CTT mice (Fig. 4A).