While HT mice show almost exclusively Pkd1+/− renal cells but do not display cysts, reproducing the background cell environment found in ADPKD type 1 patients, CY mice have renal cysts presumably formed by Pkd1−/− cells, reproducing the ADPKD type 1 cystic phenotype and its expected consequences. This evidence concerns the gene PKD1 and Renal cyst.