Sterile inflammatory infiltrates are present in the liver of Tfpi^−/−:Par4^−/− mice. Livers were isolated from Tfpi^−/−:Par4^−/− mice (first and second columns) and Par4^−/− mice (third column) and processed for immunohistochemistry. Serial sections were stained for T lymphocytes (first row, CD3-positive cells), neutrophils (second row, Ly6B.2-positive cells), macrophages (third row; F4/80-positive cells), and fibrin(ogen) (fourth row). Two types of lesions were observed in Tfpi^−/−:Par4^−/− mice: smaller lesions containing predominantly CD3⁺ cells and macrophages that were associated with fibrin deposition (first column) and large, necrotic, fibrin-rich lesions containing neutrophils that were surrounded by CD3⁺ cells (second column). Staining of tissue from Par4^−/− mice (third column) served as a control. In each image, lesions are indicated with arrowheads, and the central vein is indicated with the letter V. Slides were examined at room temperature using Olympus 10X UPlanFI and ×20 Plan objectives lenses mounted to a Olympus BX50 microscope. Coverslips were mounted using xylene-compatible mounting medium (Dako). Images were captured with a Nikon DS-Fi1 digital microscope camera and Nikon NIS Elements software (version 2.1).