Distinct from prior research, we also found that the proportions of mitochondrial COX-2 and Drp1 were increased in HCC tissues and cell lines, and indicated that the relative expression level of COX-2 was positively correlated with that of Drp1, while Drp1 expression was also negatively associated with overall survival of HCC patients. The gene discussed is PTGS2; the disease is hepatocellular carcinoma.