The results of the measurement of cytochrome c oxidase to detect the activity of complex IV using 3’, 5’-diaminobenzidine, and horse heart cytochrome c, showed that the activity remains similar in all groups, there are no statistical differences, corroborating that the activity of this complex is not modified in HCC or by IFC-305 administration. This evidence concerns the gene CYCS and hepatocellular carcinoma.