The expression levels of the MUPCDH mRNA and MUPCDH protein were confirmed using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analysis, respectively; significant repression of MUPCDH gene expression levels was observed in both ADPKD renal tissues and WT9-7 cells, compared with non-ADPKD renal tissues and HRCE cells (Fig. 2a–d). This evidence concerns the gene CDHR5 and autosomal dominant polycystic kidney disease.