We found that the expression levels of both markers were gradually increased in cyst-lining epithelial cells in Pkd1 knockout kidneys, especially at postnatal day 21, while they were only localized in the interstitium in Pkd1 heterozygous mouse kidneys and early-stage Pkd1 mutant mouse kidneys (Figure 3c,d). The gene discussed is PKD1; the disease is cyst.