Inflammatory challenge of WT EPCR^WT/R84A and EPCR^R84A/R84A mice. Mice were given an intraperitoneal injection of LPS (1 mg/kg). At 0, 2, 4, 6, and 8 hours post-LPS injection; blood samples were collected via the IVC. (A) TAT, (B) APC, and (C) IL-6 levels were measured by ELISA. (D) Lung tissue was collected from mice 24 hours post-LPS injection and snap-frozen in liquid N₂ and lung MPO activity was measured as described in “Materials and methods.”