For example, the 7 cases initially diagnosed with HES were split between molecular group 1 (n = 1), group 2 (n = 2) and group 3 (n = 4) and the 9 cases with SF3B1 mutations had been diagnosed with 7 different entities, including HES (n = 2) and 6 WHO-defined subtypes of myeloid neoplasms. The gene discussed is SF3B1; the disease is hypereosinophilic syndrome.