ADPKD shows genetic heterogeneity, with at least three different genes implicated: the PKD1 gene (85% of the cases), the PKD2 (15% of the cases), and probably a PDK3 gene (not yet identified). PKD1 gene was identified more than a decade ago, the development of treatment strategies has been hampered by a lack of understanding of the function of polycystin-1 (PC1), the protein encoded by the PKD1 gene. However, a new function of PC1 has been recently identified, which suggests a possibility for future treatment options. Indeed, it has been reported that PC1 tail interacts with tuberin, the product of the TSC2 gene. The main function of tuberin is to inactivate the Ser/Thr kinase mTOR which, in turn, promotes phosphorylation of two proteins, S6-kinase and 4E-BP1. mTOR activity has been linked to increased cell growth, proliferation, apoptosis and changes in differentiation. Researchers have subsequently shown that in ADPKD experimental animal models cyst lining epithelial cells exhibited very high mTOR activity, and hypothesized that PC1 normally suppresses mTOR activity and that defects in PC1 (and in other proteins) lead to aberrant mTOR activation. Of interest, all these proteins are localized to primary cilia or renal epithelial cells or to the basal bodies from which cilia emanate. This finding has led to the view that loss of cilia function leads to cysts formation in the kidney. The finding that mTOR is inappropriately activated in polycystic kidney disease mouse models suggests that mTOR activation may be a consequence of the loss of cilia function. If mTOR is such a converging point, it would be worthwhile as possible drug target for treatment of renal cystic disorders.