ARG1 and pancreatic neoplasm: While there was no difference in the abundance of cells expressing iNOS, a marker of M1 classically activated (pro-inflammatory) macrophages [54], significantly fewer cells expressing ARG1, a marker of M2 alternatively activated (anti-inflammatory) macrophages [54] were observed in KCI pancreas (Figure 6I,J), suggesting that pancreatic Prkci expression plays a role in the establishment of the immunosuppressive tumor microenvironment permissive for pancreatic tumor progression [50,55,56,57].