In a recent article, elevated serum ECP levels have been associated with poor disease control in chronic spontaneous urticaria (CSU), suggesting its potential as a predictive biomarker; in our study, we found a markedly high levels of ECP in patients suffering from I-HES, highlighting the varying roles of ECP across different eosinophil-associated disorders (13). Here, RNASE3 is linked to hypereosinophilic syndrome.