Localization of FVIII in macrophages in spleen and liver. (A) Liver section of a VWF-deficient mouse treated with recombinant FVIII (0.25 μg) stained with anti–mouse CD68 antibody. (B) Same liver section as depicted in panel A, but stained with monoclonal anti–human FVIII antibody LE2E9. (C) Merged image of panels A and B. (D) Spleen section of a VWF-deficient mouse treated with recombinant FVIII (0.25 μg) stained with anti–mouse F4/80 antibody. (E) Same spleen section as depicted in panel A, but stained with monoclonal anti–human FVIII antibody LE2E9. (F) Merged image of panels D and E. Both organs were collected 5 minutes after injection.