As shown in Figure 4B, the area under the ROC curve in patients with chronic viral hepatitis C to estimate significant (F≥2) and advanced (F≥3) fibrosis with the serum OPN level were 0.75 (95% CI: 0.62–0.84) and 0.81 (95% CI: 0.68–0.89), respectively. The gene discussed is SPP1; the disease is chronic hepatitis C virus infection.