The invention relates to isolated and/or recombinant nucleic acids which encode a human chemotactic cytokine designated human eotaxin, and to isolated and/or recombinant human eotaxin proteins or polypeptides, including synthetic polypeptides. The invention further relates to recombinant nucleic acid constructs, comprising a nucleic acid which encodes a human eotaxin, a portion thereof, or a variant; to host cells comprising such constructs, useful for the production of recombinant human eotaxin; and to antibodies reactive with human eotaxin, useful in in vitro methods, diagnosis and/or therapy. Also provided are methods of use of the eotaxin proteins, e.g., in the recruitment of eosinophils to a particular site or in the treatment of allergic conditions. Human eotaxins can be used to identify inhibitors (e.g., antagonists) or promoters (agonists) of human eotaxin, which can be used to selectively modulate leukocyte function, in inflammatory and autoimmune diseases, or in infections.