Figure 1.

The Figure shows the overall architecture of the microenvironment in the bone marrow as well and the localization of the indicated progenitors with specific microenvironment. Note that because of the abundance of sinusoids and CXCL12- and SCF-producing perivascular cells virtually all cells are proximal to both of these structures. Also note that most types of stem cells and progenitors have been imaged with a limited number of partner cells. Therefore, it is likely that some of the structures depicted overlap (e.g. both erythroid progenitors and HSC have been shown to localize to SCF-producing perivascular cells). The precise location of most multi and oligopotent progenitors remains unknown.