Increased circulating miR-122 levels correlate with serum ALT, AST and miR-155 levels in chronic HCV-infected patients. A. 100ul of serum was used for total RNA isolation from both healthy controls (n = 12-13) and chronic HCV patients (n = 33) with miRNeasy kit (Qiagen). Serum miR-122 levels were detected with TaqMan miRNA assay as described in the methods. The non-parametric Mann–Whitney test was used for statistical analysis. B. Serum ALT or AST levels of healthy and chronic HCV-infected individuals. C-E. Correlation between serum miR-122 and ALT (C) and AST (D) and serum miR-155 (E) was determined with the Spearman method.