Dihydroorotate dehydrogenase (DHODH) is a crucial enzyme located in the inner mitochondrial membrane, playing a vital role in the de novo pyrimidine biosynthesis pathway. It catalyzes the conversion of dihydroorotate to orotate, which is the fourth and only redox step in this pathway. This process is essential for the production of pyrimidine nucleotides, which are fundamental for DNA and RNA synthesis. DHODH is a flavoprotein that relies on ubiquinone (CoQ) for its function, and its activity is closely linked to the mitochondrial electron transport chain. Additionally, DHODH has garnered attention in cancer research due to its role in tumor cell proliferation and its potential as a target for cancer treatment.