The USC-UCLA Drug-Induced Liver Injury Clinical Center (CC) proposal in response to RFA-DK-22-013 “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 9.8 M residents of Los Angeles County (2022) 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 herbal and dietary supplements (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 DILI case from under represented populations and HDS agents with proposed biospecimens collections for future studies.; 2) Specific Aim 2: Mechanism of cell death and the role of innate immunity in Immune-Mediated Liver Injury due to Checkpoint Inhibitors (ILICI) (Ancillary Study); 3) Specific Aim 3: Proposed Clinical Treatment Trial for Cholestatic and Acute Liver Injury and 4) Specific Aim 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. .