PDGFRA and hypereosinophilic syndrome: Recent studies tested the putative efficacy of Benralizumab in other diseases, such as PDGFRA-negative hypereosinophilic syndrome [7], chronic obstructive pulmonary disease and peripheral eosinophilia [8], severe chronic rhinosinusitis with nasal polyps [9], chronic spontaneous urticaria [10,11], as well as in rare eosinophil mediated diseases (eosinophilic cystitis, fasciitis, pancreatitis, and cholangitis, Kimura’s disease, eosinophilic cellulitis, eosinophilic granulomatosis with polyangiitis, eosinophilic pneumonia, and hypereosinophilic syndrome) [12,13,14,15].