When analyzing the statistically significant differences in duration of basophilia among patients that did vs. did not present pre-myelofibrosis bone marrow fibrosis, a possible explanation might be that the action of TGF-β1 secreted by myelofibrosis megakaryocytes acts on both bone marrow fibroblasts as well as on the common basophilic-eosinophilic precursor (11, 12). The gene discussed is TGFB1; the disease is primary myelofibrosis.