CDHR5 and autosomal dominant polycystic kidney disease: However, our analysis had the following limitations: 1) the sample size was relatively small, especially that of the 100% methylation group; 2) the average interval between the baseline and final value was 21 months years; and 3) MUPCDH is mainly expressed in proximal tubular cells, whereas cysts in ADPKD originate from both proximal and distal tubules, explaining a weak correlation with disease progression.