The cover photo shows a computer-generated model of human granulocyte-macrophage colony-stimulating factor. The epitopes of a series of monoclonal antibodies which neutralize GM-CSF biological activity are highlighted in yellow or red. The epitope of a non-neutralizing monoclonal antibody is highlighted in purple. Additional information can be found in Kanakura et al, "Identification of Functionally Distinct Domains of Human Granulocyte-Macrophage Colony-Stimulating Factor Using Monoclonal Antibodies," page 1033.