Paul Ehrlich first described mast cell or mastzellen 'in 1878 based on their unique staining characteristics and their large granules content. Mast cells are normal members of the cell population in the fibrillar connective tissue. Mast cells can be found in large numbers wherever the body is in contact with its environment, eg the skin, the respiratory system and the digestive tract. This selective accumulation at sites where foreign material attempts to invade the host tissue suggests that mast cells are among the first cells to initiate defense mechanisms. Mast cells are increasingly being recognized as the key cells for connective tissue homeostasis, remodeling and repair.Mast cells play important roles in maintaining a healthy physiology, and angiogenesis in wound healing and defense against a whole host of pathogens, participating in both innate and adaptive immunity.