Neutralization of interferon-γ does not ameliorate IL-4–induced disease. Hemoglobin, polymorphonuclear leukocytes, and platelet values for mice treated with micro-osmotic pumps containing PBS or IL-4 (1 μg/hour, 3 mice in each group) for 3 days with or without neutralizing anti–IFN-γ monoclonal antibody. When the neutralizing antibody was present, IFN-γ levels were not detectable in the serum for the duration of the experiment. ns indicates not significant.