NOS3 and colitis: Regarding the mechanism by which MT1‐MMP contributes to IA and colitis, our results show that MT1‐MMP EC deficiency results in decreased NO‐dependent vasodilation of cremaster muscle arterioles and capillaries in vivo and establish that MT1‐MMP catalytic activity is required for NO production by ECs in vitro, regulating both eNOS protein and mRNA levels.