KYAT3 (kynurenine aminotransferase 3) is a mitochondrial enzyme that catalyzes the transamination of L-kynurenine to kynurenic acid, a key intermediate in tryptophan catabolism 1. This enzyme plays a critical role in regulating kynurenine metabolism; exercise-induced upregulation of KYAT3 in muscle tissue reduces plasma kynurenine levels and prevents kynurenine-induced depression-like behavior in mice 1. KYAT3 has broader transaminase activity toward multiple amino acids using glyoxylate as an amino group acceptor. In disease contexts, KYAT3 shows altered post-translational modification patterns in idiopathic pulmonary fibrosis (IPF), with increased lysine succinylation detected in lung tissues from IPF patients, suggesting mitochondrial dysfunction involvement in disease pathogenesis 2. Additionally, rare germline variants in KYAT3 have been identified in familial medulloblastoma cases, implicating potential roles in metabolic reprogramming relevant to tumorigenesis 3. KYAT3 deregulation in circulating extracellular vesicles from tuberculosis patients suggests altered kynurenine metabolism contributes to deregulated immune responses in infection 4. These findings position KYAT3 as a therapeutic target for metabolic intervention in neuropsychiatric, pulmonary, and infectious diseases.