We have observed a negative correlation between bone marrow fibrosis grade and serum levels of the IFN-γ induced cytokines CXCL9 (an antifibrotic monokine secreted by macrophages) and CXCL10 (another monokine secreted by several cell types including by macrophages, endothelial cells and fibroblasts). Here, CXCL10 is linked to primary myelofibrosis.