IFNLs were increased in both viral (>10-fold IFNL1, IFNL2/3 HCV vs. healthy) and non-viral (e.g., ~2-fold IFNL1, IFNL2/3 NAFLD/NASH vs. healthy) liver disease (Figure 6A), indicating that chronic inflammatory conditions can increase hepatic IFN-λ expression to facilitate the generation of inflammatory macrophages in vivo. Here, IFNL1 is linked to metabolic dysfunction-associated steatohepatitis.