Genes whose expression differ between that in eosinophils collected from atopic dermatitis patients of the exabartation stage and those of the remission stage were searched via a differential display method. As a result, NOR-1 (MINOR) gene was successfully identified whose expression significantly increased in eosinophils of patients in the remission stage, a stage associated with a decrease of eosinophils. The present inventors discovered that the gene can be successfully employed in testing for allergic diseases and screening for candidate compounds for therapeutic agents.