In detail, it has been demonstrated that in high-risk preschool children (at a mean age of 22 months), high feNO levels were associated with increased risk for school-age asthma [77], and in preschool children with symptoms suggestive of asthma, both feNO and specific IgE to inhalant allergens were associated with asthma at 8 years [78]. Here, IGHE is linked to asthma.