The gold standard of assessing liver fibrosis is liver biopsy, which is invasive and not without risk. Therefore, searching for noninvasive serologic biomarkers for liver fibrosis is an importantly clinical issue. Methods: A total of 16 healthy volunteers and 45 patients with chronic hepatitis C virus (HCV) were enrolled (F0: n = 16, F1: n = 7, F2: n = 17, F3: n = 8 and F4: n = 13, according to the METAVIR classification). Three serum samples of each fibrotic stage were analyzed by two-dimension difference gel electrophoresis (2D-DIGE). The differential proteins were identified by...