NUDT19 is a nudix hydrolase that functions as a fatty acyl-CoA diphosphatase, hydrolyzing acyl-CoA esters into acyl-4'-phosphopantetheine and adenosine 3',5'-bisphosphate with highest activity toward medium-chain fatty-acyl-CoA esters 1. The enzyme also exhibits decapping activity toward dpCoA-capped RNAs in vitro 2. NUDT19 resides in peroxisomes and regulates intracellular CoA pools, a key mechanism for modulating energy metabolism 3. In hepatocytes, NUDT19 knockdown increases mitochondrial ATP production by 41% and enhances fatty acid oxidation, suggesting it negatively regulates hepatic lipid metabolism 1. NUDT19 has been identified as a causal target for diabetic nephropathy risk through Mendelian randomization analysis, with druggability potential 4. In hepatocellular carcinoma, NUDT19 activation by lncRNA LINC00958 promotes epithelial-mesenchymal transition via mTORC1/P70S6K signaling 5. Additionally, NUDT19 is part of a fatty acid metabolism-related gene signature predictive of prostate cancer prognosis and therapeutic response 6. These findings establish NUDT19 as a key regulator of cellular energy metabolism with implications for metabolic and malignant diseases.