AIF1 and neoplasm: More importantly, activated macrophages as identified by allograft inhibitory factor‐1 (AIF‐1) + cells (Fig. 4C) and tumor‐associated neutrophils or granulocytic myeloid‐derived suppressor cells (G‐MDSCs) as identified by Ly6G+ cells (Fig. 4D), were found to be significantly decreased in KPC2 tumors from Plg− mice relative to those harvested from Plg+ mice, suggesting that plasmin(ogen) promotes recruitment of immune cells that support an immunosuppressive tumor microenvironment.