The mRNA expression of POLD1 was detected in HCC cells cultured with serum containing Smilax china L. The expression levels of POLD1 mRNA in the high and low concentration groups (0.45±0.1 and 0.28±0.06) were significantly different from the POLD1 mRNA expression levels in the blank group (P<0.05; Table III and Fig. 3). The gene discussed is POLD1; the disease is hepatocellular carcinoma.