Abstract: A method of treating an immunologic, proliferative, or infectious disease in a warm-blooded animal is disclosed. The method comprises administering to the animal omega interferon (IFN) at a dosage and activity for the disease state treated sufficient to induce a therapeutic response in the animal, which dosage and activity for the disease state treated is higher than would be well-tolerated based on data for non-omega IFN's. The omega IFN is administered alone or In combination with a therapeutically effective amount of at least one adjunctive therapeutic agent. Also disclosed is an article of manufacture useful for treating an immunologic, proliferative, or infectious disease, which article comprises (1) omega IFN in a form suitable for administering a therapeutically effective amount of the omega IFN to the subject in order to induce the desired therapeutic response (2) instructions for administering the omega IFN as desired, that is higher than would be well-tolerated based on data for non-omega IFNs.