All the members of the CYP450 superfamily were shown to be significantly downregulated in HCC tissues compared with their expression in normal tissues [53], and two isoforms (CYP2C9 and CYP2E1) were found in lower abundance in high-grade HCC tumors, implying that substrates such as antitumor drugs may be eliminated more slowly and achieve higher concentrations [53]. The gene discussed is CYP2E1; the disease is hepatocellular carcinoma.