Recent findings suggest that during HAV-related clinical courses, increased levels of IL-17F may play a protective role against allergies by reducing IgE levels, and this is supported by the trend toward IgE level reduction in HAV-infected patients with a CBR >2 mg dl−1 who also show the highest levels of IL-17F.30 Thus, discrete CBR levels resulting from infection may drive anti-inflammatory immune responses that, in turn, may protect against allergens or autoimmune mediators. This evidence concerns the gene IGHE and infection.