During the process of screening potential eligible studies, we set the inclusion and exclusion criteria similar to the previous meta-analysis and thus 2 studies that used plasma as the sample to explore the diagnostic value of DKK-1 in HCC diagnosis were excluded.[24,25] It was also a consideration of homogeneity because biomarkers examined by different samples were in very dynamic concentrations.[41] There was no limitation in language of included articles in the previous meta-analysis, but in the present meta-analysis, only articles published in English were included. This evidence concerns the gene DKK1 and hepatocellular carcinoma.