In contrast to the hippocampal neurogenic niche, allergy elevated the number of Iba1+ microglia in the granular cell layer of the OB (control: 9890 ± 546 cells/mm3, allergy: 11271 ± 985 cells/mm3; p < 0.0027) (Figure 4B). The gene discussed is AIF1; the disease is allergic disease.