The area under the ROC curve (AUC-ROC) indicated that circ_104075 (AUC-ROC: 0.973) might be a better serum predictor for HCC compared to other non-coding RNA biomarkers (DANCR, AUC-ROC: 0.851; HULC, AUC-ROC: 0.855; miR-223, AUC-ROC: 0.818; miR-21, AUC-ROC: 0.782; UCA1, AUC-ROC: 0.735) (Fig. 8c) and classical protein biomarkers (AFP, AUC-ROC: 0.750; DCP, AUC-ROC: 0.771; AFP-L3: 0.766) (Supplementary Figure 2A). Here, AFP is linked to hepatocellular carcinoma.