Based on the ROC curve, the optimal cutoff value of serum thioredoxin levels as an indicator for auxiliary diagnosis of HCC was projected to be 20.9 ng/mL, which yielded a sensitivity of 84.1% and a specificity of 91.6%, with the area under the curve at 0.941 (95% CI, 0.918–0.963). Here, TXN is linked to hepatocellular carcinoma.