Table 2.

Basophil‐derived mediators and cytokines and their possible role in the pathogenesis of CML

Mediator/antigen	Biological effects	Potential role in the pathogenesis of CML
Tryptase	Fibroblast proliferation Endothelial cell growth	BM fibrosis Increased BM angiogenesis
HGF	Fibroblast proliferation Endothelial cell growth	BM fibrosis Increased BM angiogenesis
Angiopoietin‐1	Endothelial cell growth	Increased BM angiogenesis
VEGFa	Endothelial cell growth Vascular permeability‐mediated redistribution of leukocytes	Increased BM angiogenesis Extramedullary spread of leukocytes and stem cells
Histamine	leukocyte homing by selectin‐regulation	Extramedullary spread of leukocytes and stem cells
CD26	Mobilization of myeloid stem and progenitor cells through degradation and inactivation of SDF‐1	Extramedullary spread of stem cells, with consecutive myelopoiesis in various extramedullary organs

BM, bone marrow; CML, chronic myeloid leukaemia; HGF, hepatocyte growth factor; SDF‐1, stroma cell‐derived factor‐1; VEGF, vascular endothelial growth factor.

^aActivated basophils reportedly express and release VEGF‐A and VEGF‐B.