AREG and pneumonia: In the lung of anti–PD-L1–treated mice, we noticed a reduced expression of genes encoding for factors associated with resolution of inflammation and tissue healing in IAV-induced pneumonia (module 2) as compared to controls such as Areg (41), Igf1 (42), Csf2 (43), Tgfb1 (44), Ptges2 (45), and Il17rb (46), as well as genes encoding for angiogenic factors (Vegfa) (Fig. 8H) (47).