Solid tumors are consistently less oxygenated than the normal tissues from which they arose. Associations between tumor hypoxia and aggressively malignant phenotypes are observed across a range of cancers. Clear cell renal cell carcinoma is characterized by a loss of the tumor suppressor gene VHL that leads to a constitutive hypoxic response. As such, it represents a model system for tumor hypoxia in general. In the current research project we aim identify and characterize the different cell types from which kidney cancer is thought to develop, and to characterize how they respond to loss of VHL. Filtration and selective transport of molecules represents a key function of the normal kidney. We are therefore exploring whether transport proteins might represent a particularly attractive source for identification of novel biomarkers for kidney cancer.