TWF1 and colitis: Since TSP1 was stained with the monoclonal antibody A6.1, which recognizes an epitope downstream of the predicted TSP1 cleavage sites for MT1‐MMP (Annis et al, 2006), this pattern is consistent with TSP1 cleavage by endothelial MT1‐MMP during DSS‐induced colitis leading to TSP1 paucity around MT1‐MMP‐expressing vessels in MT1f/f mice (Fig 6B and C) and to its release to the serum.