EPX and Alzheimer disease: Importantly, while the number of infiltrating leukocytes - including eosinophils, mast cells, and CD4+ T cells - was not significantly altered by treatment, the activity of eosinophils and mast cells was suppressed, as indicated by significantly reduced eosinophil peroxidase (EPX) activity and lowered serum histamine levels in 17-AAG-treated AD mice.