The human mast-cell population is composed of a heterogenous group of cells with respect to structure and function. Mast-cells can no longer be regarded simply as cells that initiate acute allergic reactions through the release of rapidly metabolized mediators, such as histamine and products of arachidonic acid oxidation. The production of a wide range of cytokines by mast-cells in the centre of the allergic inflammation. These cytokines influence migration and activation of other different cells including basophils and eosinophils and also lymphocytes, thus perpetuating allergic inflammation. Mediators release from human basophils are considered to contribute to the late phase of allergic response.