MMP9 and deep vein thrombosis: While it has been established that MMP9 activity in lymph fluid (Pan et al., 2014), lung tissue (Zheng et al., 2021), and liver (Biron-Pain and St-Pierre, 2012) of CLP mice is significantly increased, the expression of MMP9 in the inferior vena cava in CLP-induced DVT model remains unclear.