Our data show that the serum level of cathepsin B is only a moderate biomarker to detect minimal fibrosis in F1 patients (AUROC = 0.68 ± 0.09), but is an excellent biomarker to detect intermediate levels of fibrosis in F2 patients (AUROC = 0.992 ± 0.006), and in advanced liver fibrosis in F3 (AUROC = 0.98 ± 0.01) and F4 patients (AUROC = 0.95 ± 0.02). This evidence concerns the gene CTSB and fibrosis.