In unselected adult-onset asthma patients the diagnostic utility of total IgE, as a single biomarker, is poorer compared to either fractional exhaled nitric oxide (FeNO) or blood eosinophils, while the combination of FeNO and blood eosinophils further enhances the diagnostic efficacy regardless of asthma phenotype [43]. This evidence concerns the gene IGHE and asthma.