In the present study, we show the cellular effect of CaSR activation with NPS-R568 on the most proximal events in ADPKD pathogenesis, calcium and cAMP, in ciPTEC of human proximal tubule origin stably knocked down for PKD1 or isolated from the urine of an ADPKD1 patient. The gene discussed is CASR; the disease is autosomal dominant polycystic kidney disease.