In line with these findings, another suggestion on the involvement of leptin signaling in the modulation of antigen-induced arthritis comes from studies showing that leptin-or leptin receptor (LepR)-deficiency protects mice from the development of autoimmune arthritis, after immunization with methylated bovine serum albumin (BSA) into knee joints, as these genetic conditions associate with decreased antigen-specific T cell proliferative responses (118). The gene discussed is LEP; the disease is arthritic joint disease.