The significance of Sema3A in regulating immune-mediated inflammation has been widely reported; for example, the expression level of Sema3A in the epidermis of patients with AD and psoriasis was remarkably decreased compared to that in healthy volunteers28; in the epidermis of patients with AD, epidermal hyperinnervation and high levels of nerve growth factor (NGF) were observed29. This evidence concerns the gene NGF and Alzheimer disease.