A method of treating chronic pain, local inflammation, or systemic inflammation, comprising administering to a human patient in need thereof an effective amount of a pharmaceutical composition that comprises:(a) a fusion protein consisting of, from N- to C-terminal, a human IL-4, a linker, and a human IL-10;
- or from N- to C-terminal, a human IL-10, a linker, and a human IL-4;
- and (b) a pharmaceutically-acceptable excipient, carrier, or diluent;
- wherein the human IL-4 consists of an amino acid sequence with at least 99% sequence identity to SEQ ID NO:
- 1, the linker consists of the amino acid sequence of SEQ ID NO:
- 3, and the human IL-10 consists of an amino acid sequence with at least 99% sequence identity to SEQ ID NO:
- 2;
- and wherein the effective amount is 0.5 μg to 1 mg per kg of body weight of the patient.