In the past year insights have been gained into mechanisms whereby eosinophils are mobilized from the vasculature to enter sites of inflammation. In addition, the responses of eosinophils to specific cytokines have been delineated. Moreover, for the first time it has become clear that eosinophils themselves are sources of cytokines that may exert not only autocrine effects on eosinophils but also paracrine effects on adjacent cells within tissues.