Eosinophils, as major effector cells in the inflammatory response by perivascular infiltration and releasing granule proteins (e.g., major basic protein, eosinophil cationic protein, eosinophil peroxidase, or EDN), have been implicated in the pathogenesis of many diseases, among others atopic dermatitis, urticaria, and asthma [32,33,34]. Here, RNASE2 is linked to urticaria.