MSTN and hepatocellular carcinoma: Time-dependent areas under receiver operating characteristic (AUROC) curve of serum AFP levels to predict development of HCC were significantly lower than those of serum myostatin (p < 0.001 by DeLong test): Serum AFP, 0.57 (95% confidence interval [CI], 0.54–0.60) and serum myostatin, 0.78 (95% CI, 0.71–0.84), respectively.