Mutations in cilia genes drive renal cyst formation in patients and in mouse models of the disease. Multiple forms of renal cystic disease are a leading cause of end stage renal disease and cause considerable morbidity in society. There are no therapies designed to stop cyst formation and the cellular and molecular mechanisms of cyst formation are not well understood. We have identified the ciliary trafficking gene Tulp3 as an essential regulator of renal cystic disease. Mutations in cilia genes have been shown to cause kidney cystogenesis and to perturb the Hedgehog signaling pathway in many in vivo and in vitro contexts. We aim to test whether the activation of the Hedgehog pathway in vivo in renal cells causes cyst formation in a mouse model. Understanding the cellular and molecular mechanisms by which perturbations in cell signaling can initiate the cystic process will be invaluable to our understanding of the disease. A better understanding of the molecular mechanisms of how cyst formation arises will open new strategies to pharmacologically control/contain cystogenesis.