Platelet‐derived growth factor receptor beta (PDGFRB) rearrangement has been reported in a number of patients with chronic eosinophilic leukemia (CEL), B‐acute lymphoblastic leukemia, myeloproliferative neoplasms, and juvenile myelomonocytic leukemia. This evidence concerns the gene PDGFRB and Chronic Eosinophilic Leukemia, Not Otherwise Specified.