A method of inducing arthritis in an animal to provide an animal model for the study of arthritis, comprising administering to said animal an arthritis inducing amount of a composition comprising one or more proteins selected from the group consisting of pig heparin binding 38 kDa protein, bovine 39 kDa whey protein, murine breast regressing 39 kDa protein, (brp39), human oviduct-specific glycoprotein, murine oviduct-specific glycoprotein, hamster oviduct-specific glycoprotein, bovine oviduct-specific glycoprotein, human chitotriosidase precursor protein, and murine secretory protein YM-1 precursor, and fragments of the foregoing proteins that will induce arthritis in an animal, together with a pharmaceutically acceptable carrier.