The fluorescence of cells which were infected with shCtrl or shPOLQ plasmids for 72 h, observed by microscope demonstrated a > 80% efficiency of infection and the normal cell condition (Fig. 2C).Moreover, the mRNA and protein expression levels of POLQ were downregulated in BEL-7404 (Fig. 2D) and SK-HEP-1 (Fig. 2E), respectively, proving the successful construction of POLQ knockdown HCC cell lines. The gene discussed is POLQ; the disease is hepatocellular carcinoma.