The incidence has been reported to be 0.036/100,000 for HES in the USA (57) and 0.018/100,000 specifically diagnosed with the most prevalent primary eosinophilia, a factor interacting with PAPOLA and CPSF1-platelet-derived growth factor receptor alpha (FIP1L1-PDGFRA)-positive neoplasms, in France (58). Here, PDGFRA is linked to hypereosinophilic syndrome.