Used in immunotherapy research for modulating T-cell responses, particularly in cancer and autoimmune diseases. Binds selectively to OX40 (CD134), a co-stimulatory receptor on activated T cells, enhancing T-cell proliferation, survival, and effector function. Investigated for its potential to boost anti-tumor immunity by promoting memory T-cell development and improving checkpoint inhibitor therapies. Also studied in adoptive cell therapies and vaccine adjuvants to strengthen immune activation. In autoimmune contexts, blocking OX40 signaling may help suppress pathological immune responses.