TNFRSF4 and rheumatoid arthritis: Building on this potential, anti-OX40-specific mAbs were developed to monitor OX40 expression on activated T cells in preclinical mouse models and used in noninvasive medical imaging of OX40 in cancer vaccination (38), T cell response to glioblastoma (39), acute graft-versus-host disease (40), and rheumatoid arthritis (41).