In addition, we also found that AdipoQ levels in HCC patients were not related to gender(man vs woman: SMD = − 0.29, 95% CI (− 0.69, 0.11), P = 0.153) and vascular invasion (present vs absent: SMD = 0.19, 95% CI (− 0.11, 0.49), P = 0.208). This evidence concerns the gene ADIPOQ and hepatocellular carcinoma.