Figure. 6.

The maturation of mast cell populations is shown here. The myeloid progenitor begins as a CD34⁺ cell that leaves the bone marrow and matures into a myeloblast and then into neutrophils and monocytes or into a circulating mast cell progenitor, which now expresses MCP-7. This cell becomes a mature mast cell that weakly expresses TNFa, FCER1G, and MPO and is involved with degranulation upon exposure to antigen, is involved with the enhancement of inflammation, or can be active in the tumor microenvironment by producing multiple cytokines. In the MRL mouse, increased numbers of mast cells at the regenerative site show increased MPO levels, but the tissue is strikingly low in FCER1G, a marker of mast cell maturity, and high in MCP7. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound