A key contributory event in the initiation of fibrosis in ADPKD, is the inheritance of germline mutations in the PKD1 [9,10,11,12] or PKD2 [13] genes, which encode for the two polycystin proteins which co-localise in the primary cilia and other compartments [14] and interact with each other [15]. The gene discussed is PKD1; the disease is autosomal dominant polycystic kidney disease.