Dihydroorotate Dehydrogenase is an enzyme that plays a crucial role in the synthesis of pyrimidines, which are essential building blocks for DNA and RNA. It catalyzes the conversion of dihydroorotate to orotate, using NAD+ as a cofactor. This reaction is a key step in the de novo pathway of pyrimidine nucleotide biosynthesis. The enzyme is found in various organisms, including humans, and is located in the mitochondria in mammals. Inhibitors of dihydroorotate dehydrogenase are being studied for their potential use in treating autoimmune diseases and certain types of cancer, highlighting its importance in cellular metabolism.