Gross appearance of 3-day-old punch biopsy wounds. Punch biopsy wounds were placed on the backs of wild-type (WT) and hemophilia B (HB) mice as described in “Materials and methods.” These representative photos show that both achieved hemostasis, but the wounds on HB mice tended to be larger and with dark coloration (arrow) due to red blood cells in the clot. The HB mice also developed subcutaneous hemorrhage with discoloration of the overlying skin (arrowheads).