AFP and hepatocellular carcinoma: As shown in Figure 5, the combination of hsa_circ_0028861 and AFP exhibited better diagnostic performance than AFP alone in differentiating HCC patients from chronic HBV patients (AUC: 0.91 vs. 0.82; Figures 5A,D and Table 5), cirrhosis patients (AUC: 0.82 vs. 0.69; Figures 5B,E and Table 5), or the combination of chronic HBV and cirrhosis patients (AUC: 0.86 vs. 0.76; Figures 5C,F and Table 5).