IL-28A serum protein levels were significantly higher in patients with viral infection (mean concentrations of 52.2 pg/ml in HCV and 46.3 pg/ml in HBV patients) in comparison to non-viral liver diseases such as PBC (mean concentration 14.9 pg/ml; p<0.01 vs. HCV/HBV), PSC (mean concentration 21.2 pg/ml; p<0.05 vs. HCV/HBV) or a control group (mean concentration 23.6 pg/ml; p<0.05 vs. HCV/HBV) (Fig. 5C). Here, IFNL2 is linked to primary biliary cholangitis.