In order to understand the role of DNASE1L3 in the progression of HCC, we used TCGA (The Cancer Genome Atlas) and GEO (Gene Expression Omnibus) databases to compare the differences of DNASE1L3 mRNA level between tumour samples and normal samples, and to investigate the role of DNASE1L3 in the outcome of HCC patients. The gene discussed is DNASE1L3; the disease is hepatocellular carcinoma.