NDUFA4L2 expression is upregulated in HCC tissue compared with nontumorous tissue and is associated with poorer overall survival.112 Prenyl diphosphate synthase subunit 2 (PDSS2) is an enzyme involved in the production of coenzyme Q10, which plays a critical role in the ETC. The gene discussed is COXFA4L2; the disease is hepatocellular carcinoma.