Fpr1-/- mice had higher hepatic f4/80+ macrophages (Fig. S9G), which might be secondary to lower necrosis, given that hepatic macrophage depletion occurs during early APAP-ALI,62 and that this difference was resolved at 24 h post APAP-ALI (Fig. S9H). Here, FPR1 is linked to acute respiratory distress syndrome.