More than 10 million Americans have chronic kidney disease and every year, approximately 100,000 new patients develop end stage renal disease (ESRD) resulting in incalculable human suffering, a high rate of premature mortality, catastrophic physical and emotional disability and prohibitive costs to the U.S. health care system. The current medical therapies for chronic kidney disease, which disproportionately affect African Americans and other minority groups and account for 70% of ESRD, cases are woefully inadequate. This O'Brien Kidney Research Core will create opportunities for novel insights through characterization of tissue profiles that will define new disease markers and molecular pathways and will be available to all kidney investigators on the www. It will thereby fundamentally alter the starting point for research into prevention of progression of these kidney diseases. C-PROBE is an essential element of the center grant and presents a biomedical resource core consisting of: (1) clinical phenotyping (that is, systematic identification of observable physical and biomedical characteristics) of kidney disease patients including the accurate measurement of kidney function; and (2) a specimen BioBank which will store blood, urine and kidney tissue samples . A key component of C-PROBE is therefore that it contains a proven mechanism to collect samples from high risk groups including minorities, that will feed the other Cores and provide biomedical investigators at the institutions of University of Michigan Health System, St. John Hospital, Wayne State University in Michigan and University of Illinois in Chicago access to a dynamic pool of well characterized high risk kidney disease patients and their biological specimens to conduct high caliber translational research.