GCH1 and neoplasm: In addition, antioxidant enzymes such as ferroptosis suppressor protein 1 (FSP1), which catalyzes the conversion of CoQ10 to ubiquinol, and GTP cyclohydrolase 1, which catalyzes the production of tetrahydrobiopterin, have been shown to be upregulated in some cancers, helping tumor cells escape ferroptosis and promote tumor development [15, 74].