Abstract
Bone marrow consists of specific microenvironments called "niches". The osteoblastic niche is responsible for maintenance of hematopoietic stem cells in a more primitive quiescent state, while the vascular niche maintains stem and progenitor cells proliferate and ready to begin the process of differentiation. Recently, the factor SDF-1 (stromal derived factor-1) or CXCL12 was identified a…