In particular, 90% of the content of eosinophil granules is represented by basic proteins including the eosinophil cationic protein (ECP), eosinophil-derived neurotoxin (EDN), eosinophil peroxidase (EPO), and major basic protein (MBP), which represent excellent markers of the presence and activation of eosinophils and have the potential to be used as biomarkers in eosinophil-mediated diseases such as eczema, allergic rhinitis, asthma, and food allergy [30,31,32,33]. The gene discussed is RNASE2; the disease is asthma.