HSD17B13, also known as Hydroxysteroid 17-beta dehydrogenase 13, is an enzyme mainly located in the liver that plays a role in the metabolism of steroid hormones and fatty acids. It is part of the hydroxysteroid (17-beta) dehydrogenase (HSD17B) family, which catalyzes the conversion between hydroxysteroids and ketosteroids. HSD17B13 is important for fatty acid metabolism, especially in the oxidation of long-chain fatty acids, and is found in peroxisomes—cellular organelles responsible for processing fatty acids. Its enzymatic activity is crucial for converting long-chain fatty acyl-CoAs into 3-ketoacyl-CoAs, supporting healthy liver function and lipid metabolism.