Mast cells seem to have other roles as well.
Found to congregate around wounds, they may play a part in wound healing. For example, the typical itching you feel around a healing scab may be caused by histamine released by mast cells. Researchers also think mast cells may have a role in the growth of blood vessels. No one with too few or no mast cells has ever been found, which indicates to some scientists that we may not be able to survive with too few mast cells. Systemic mastocytosis is caused by the accumulation of mast cells in the tissues and can affect organs such as the liver, spleen, bone marrow, and small intestine.