FCN2 and allergic asthma: Abdel- Aziz et al. (113) used an electronic nose tool to successfully distinguish healthy from asthmatic subjects, while Nieto-Fontarigo et al. (114), combining liquid chromatography with mass spectrometry, identified 18 serum proteins as potential biomarkers of asthma phenotypes (e.g., FCN2 and MASP1 for non-allergic asthma, or HSPG2 and IGFALS for allergic asthma) and disease severity.