MSRA (methionine sulfoxide reductase A) catalyzes the reversible reduction of oxidized methionine residues in proteins, functioning as a critical protein repair enzyme 12. Operating within cytosolic, mitochondrial, and nuclear compartments, MSRA serves as an electron acceptor in the thioredoxin antioxidant system, which provides reducing equivalents to combat oxidative stress and maintain cellular redox homeostasis 3. In cancer biology, MSRA acts as a suppressor of pancreatic ductal adenocarcinoma metastasis by preventing methionine oxidation of pyruvate kinase M2 (PKM2). MSRA loss results in selective M239 oxidation in PKM2, sustaining its active tetrameric state and promoting tumor migration and metastatic spread 4. Conversely, MSRA expression is significantly reduced in metastatic PDA tumors, indicating its tumor-suppressive function. Similarly, protective genetic variants in MSRA (rs73534533 C>A) are associated with improved overall survival in nonsmall cell lung cancer patients, with differential expression analysis confirming lower MSRA mRNA levels in lung cancers compared to normal tissue 5. Beyond cancer, MSRA participates in genetic regulation of personality traits, with variants influencing risk-taking behavior and irritability across multiple personality domains 6. Clinically, MSRA functionality is essential for EGFR T790M mutant degradation in TKI-resistant lung cancers, as reduced NADPH availability impairs MsrA's capacity to counteract methionine oxidation 7.