Analysis of lungs of low-TF mice with different levels of TFPI. Low-TF mice with wild-type levels of TFPI frequently died of lung hemorrhages (A, C) and also had hemosiderin deposition in their lungs (E). In contrast, no hemorrhages or hemosiderin deposits were observed in lungs of low-TF mice with no TFPI (B, D, F). Panels A and B show macroscopic views of lungs. Panels C and D were stained with H&E. Panels E and F were stained with Prussian Blue. Original magnifications of the panels were × 40 (C and D) and × 400 (E and F). PanelsA, C, and E show lungs from TFPI^+/+/low-TF mice and panels B, D, and F show tissues from TFPI^–/–/low-TF mice.