CD4 and Alzheimer disease: Although the number of infiltrating leukocytes (Fig. 2e, f) including eosinophils (Fig. 2g), CD4+ T cells (Fig. 2h), and mast cells (Fig. 2i) in the skin was not significantly affected by the topical application of 17-AAG, circulating eosinophil percentages (Fig. 2j), serum levels of histamine (Fig. 2k), and eosinophil peroxidase (EPX) activity (Fig. 2l) in the skin were significantly reduced in 17-AAG-treated AD mice compared to vehicle-treated AD mice.