Tamoxifen-induced systemic thrombomodulin ablation in adult mice. (A-B) Residual expression of Thbd antigen detected in the lungs by western blot analysis of tissue lysate (A) and on histological sections (B). Numbers in panels A and B identify individual animals. (C) Detection of Thbd protein by immunohistochemistry in various tissues of tamoxifen-treated ERCreThbd^loxP mice. Brown staining indicates Thbd protein detected by horseradish peroxidase–coupled anti-Thbd antibody. Hematoxylin counterstain. Red bars indicate 50 μm. In several animals, Thbd antigen was virtually undetectable. (D) Kaplan-Meier survival plot of ERCreThbd^loxP mice after tamoxifen treatment at 8 to 10 weeks. Difference in survival between groups is significant (Mantel-Cox log-rank analysis). Ctrl, non–tamoxifen-treated mice.