As compared to the I2 value (37.1%) of DOR of DKK-1 + AFP in diagnosing all HCC patients, we found that the stage of HCC was the source of heterogeneity, as the I2 value of DOR decreased >10% and the I2 values of both pooled SN and SP were 0.0%. The gene discussed is AFP; the disease is hepatocellular carcinoma.