Bone marrow fibrosis in myeloproliferative neoplasms-associated myelofibrosis: deconstructing a myth?

The dominant pathophysiological and clinical features of myeloproliferative neoplasm (MPN)-associated myelofibrosis are caused by bone marrow fibrosis. It is widely believed this fibrosis is a reaction to the MPN-clone implying the cells causing fibrosis are polyclonal and genetically unrelated to the MPN-clone. We cite recent data illustrating the complexity of cell types comprising the bone marrow micro-environment and showing that at least some of the cells responsible for bone marrow fibrosis are clonal and genetically related to the MPN-clone.