NOS2 and Crohn disease: For instance, in a mouse model of Crohn's disease, succinate significantly upregulated the mRNA levels of the M1‐type markers Cd11c and iNOS [34]; in a mouse model of acute lung injury induced by intestinal ischemia‐reperfusion, succinate also induced alveolar macrophage polarization toward the M1 type as indicated by an increase in M1‐type related markers and a decrease in M2‐type markers [26].