IGHE and allergic disease: In our study, the nasal DNA methylation levels of three CpG sites were lower in symptomatic than asymptomatic IgE-sensitized participants, showing the potential of these three CpG sites in nasal epithelial cells to be a biomarker for the presence of symptoms in IgE-sensitized individuals, or in other words, to be a more selective biomarker for allergic disease.