TRIM31 is an E3 ubiquitin ligase that functions as a key regulator of innate immunity and inflammation through selective ubiquitination of multiple substrates. In antiviral defense, TRIM31 catalyzes K63-linked ubiquitination of MAVS (mitochondrial antiviral-signaling protein), promoting its polymerization and filament formation on mitochondria to activate antiviral signaling 1. TRIM31 also negatively regulates the NLRP3 inflammasome by mediating K48-linked ubiquitination of NLRP3, leading to its degradation and suppression of inflammatory responses 2. Beyond immunity, TRIM31 exhibits context-dependent roles in disease pathology. In atherosclerosis, macrophage-derived TRIM31 protects against foam cell formation by promoting K48-linked ubiquitination and degradation of LOX-1 (oxidized LDL receptor), restricting lipid uptake 3. In hypertensive nephropathy, TRIM31 suppresses renal fibrosis by targeting MAP3K7 for degradation, inhibiting TGF-β signaling 4. TRIM31 also protects against hepatic fibrosis through activation of the Nrf2 antioxidant pathway 5. Conversely, TRIM31 exhibits tumor-promoting functions in certain cancers through its involvement in p53 and other oncogenic pathways 6. These findings establish TRIM31 as a potential therapeutic target for inflammatory, cardiovascular, and hepatic diseases.