The correlation between serum PCSK9 levels and various factors, including age, BMI, AST, ALT, GGT, AP, total bilirubin, direct bilirubin and indirect bilirubin, as well as the Fibroscan score ranging from 0 (no fibrosis) to 4 (cirrhosis) and the MELD score, was determined in the entire cohort, and because male and female patients with PSC exhibited different serum PCSK9 levels (Fig. 1d), for both sexes. This evidence concerns the gene PCSK9 and fibrosis.