This study aims to investigate the role of IER2 in acetaminophen (APAP)- induced liver injury. Male C57BL/6J mice were randomized to receive a single tail vein injection of either AAV8-GFP or AAV8-Ier2. Mice were fasted overnight for 14 hours followed by intraperitoneal administration of APAP (500 mg/kg). Animals were sacrificed 8 hours post-APAP challenge, and liver tissues were collected for proteomic profiling. This study aims to characterize the proteomic changes associated with IER2 overexpression during APAP hepatotoxicity, thereby establishing a foundation for subsequent mechanistic investigations.