Based on these previous reports, we proposed that trans-activation effect of hPXR may be enhanced by fusion with a heterologous AD, and subsequently, the ability of these “chimeric hPXR” to activate CYP3A4 gene in hepatoma cells would be higher as compared to native hPXR; thus, chimeric hPXRs might be effective in producing hepatoma cells with an increased expression of CYP3A4. The gene discussed is CYP3A4; the disease is hepatocellular carcinoma.