DNA array technique was applied for the simultaneous analysis of multiple genes for the characterization of diseases and for cellular analysis. This technology implicated genes in the pathogenesis of allergic disease, which were previously not discussed in this context. This article summarizes results of gene expression profiling of allergic disease and immunologically relevant cells, using DNA array technology. The results of these studies are searchable in public databases and represent exciting tools to study gene expression of diseases on a global base.