TGM2 and allergic asthma: WT BALB/c and TG2-deficient mice with a BALB/c background (N12) (TG2−/−) were intraperitoneally administered OVA and alum (20 μg OVA + 2 mg alum) two times at a 7-day interval, and an intranasal OVA challenge (50 μg OVA) for 3 consecutive days starting on days 14 and 21 to evaluate the role of TG2 during the pathogenesis of allergic asthma.