For DCP in HCC diagnosing studies, the overall analysis merging the theoretical 33 (27 + 6) studies had little variance with the unredressed 27 studies (variance = 0.217, P = 0.000 vs. variance = 0.230, P = 0.000) and that was similar to DCP + AFP studies (variance = 0.297, P = 0.000 vs. variance = 0.341, P = 0.000); for AFP researches, none hypothetical study was added and no data were changed between adjusted and unadjusted ones (variance = 0.135, P = 0.000 for both) (Supplementary Figure 2). The gene discussed is AFP; the disease is hepatocellular carcinoma.