Project Summary/Abstract The USC-UCLA Drug-Induced Liver Injury Clinical Center (CC) proposal in response to RFA-DK-17-509 “Limited Competition for the Continuation of the Drug Induced Liver Injury Network (DILIN) Clinical Centers” hopes to continue to participate with the other CCs to advance the scientific knowledge and clinical evaluation of DILI. Our proposal will continue to combine the only two medical schools in Los Angeles County allowing us to be able to uniquely capture and enroll DILI cases into the Networks database supervised by the Data Coordinating Center (DCC). The 10.1 M residents of Los Angeles County (2016) are an unmatched resource composed of the most ethnically diverse population in the United States. Our proposal continues to utilize the expertise and talents from Keck School of Medicine of USC and David Geffen School of Medicine at UCLA. The enrollment of a large number of bona fide and ill patients with close follow up has demonstrated our CC’s ability to capture DILIN cases in this diverse populations with little overlap in etiology for DILI other than for HDS in our respective patient populations. The Specific Aims for the continuation of the USC-UCLA DILI CC are to: 1) Continued enrollment of high quality bona fide DILIN case from under represented and Pediatric populations with emphasis on increasing enrollment of acute cases; 2) Development of a treatment trial for cholestatic liver injury; 3) Development of a treatment trial for acute hepatocellular Injury; and 4) Continued support of the DILIN’s effort to develop causality assessment instruments and development of a pilot project for a pharmacovigilance protocol for adverse liver injury due to medication or HDS.