PDGFRB and myeloproliferative disorder: PDGFRB rearrangement has been reported in a number of patients with CEL, B‐acute lymphoblastic leukemia, and myeloproliferative neoplasms with neutrophilia and/or monocytosis (Cheah et al., 2014; Gotlib, 2017; Helbig et al., 2010; Jawhar et al., 2017).