We first corroborated that basophils and mast cells were increased in frequency and had an inflammatory phenotype in the setting of myelofibrosis in patients by interrogating a scRNAseq dataset of ~120,000 CD34+ Lin- HSPCs isolated from a cohort of 15 myelofibrosis patients and 6 age-matched healthy donors (9). Here, CD34 is linked to myelofibrosis.