ARG1 and peritonitis: To evaluate macrophage maturation and differentiation, peritoneal macrophages from LysMCre/+; Pros1fl/fl; and Pros1fl/fl mice were isolated 66 h post peritonitis initiation, and their protein content was immuno-blotted for the macrophage M2/maturation markers arginase-1 and CD11b as well as for the pro-resolving enzyme 12/15-LO (Figure 4).