Additionally, they found that DFMO (a partial inhibitor of arginase, an enzyme that metabolizes arginine) administered to juvenile CVN-AD knockout mice led to reduced cortical amyloidosis and recovery of cognitive function (episodic memory) via the reduction of arginine catabolism by the enzyme arginase 1 (Arg1) and subsequent reduction of immunosuppression by cerebral microglia. Here, ARG1 is linked to Alzheimer disease.