RUNX1 mutations occurred in 5 patients, including 1 patient with PDGFRA rearrangement and 4 patients with FGFR1 rearrangement, which suggested that RUNX1 mutations were associated with poor prognosis (myeloid/lymphoid neoplasms associated with eosinophilia and rearrangement of PDGFRA, PDGFRB, FGFR1, or PCM1-JAK2). Here, RUNX1 is linked to Increased total eosinophil count.