Reply

We thank Theoharides and Leeman1 for their positive comments on our review,2 which focused on recent developments in the understanding of human mast cell biology. It is gratifying to see this large number of recent scientific reports from which we selected only a portion of many interesting and novel experimental approaches and observations. The understanding of mast cell biology has lagged somewhat behind studies on other effector cells because mast cells do not normally occur in blood, there is no human condition characterized by the absence of mast cells in all tissues, and there is no pharmacologic therapy that specifically and only silences mast cell function.