In adoptive transfer assays, although similar arthritis scores were observed on day 34 in the duration curves, CD4+CD28−OX40+ T cells demonstrated a more powerful pathogenic role than the CD4+CD28−OX40−, CD4+CD28+OX40−, and CD4+CD28+OX40+ T cells in both early (days 1–33) and late (days 35–64) arthritis. This evidence concerns the gene CD28 and arthritic joint disease.