Used in cancer immunotherapy research to modulate T-cell activity by targeting the B- and T-lymphocyte attenuator (BTLA) pathway. It acts as a soluble fusion protein that binds to HVEM (herpesvirus entry mediator), blocking inhibitory signals that suppress immune responses. This enhances T-cell activation and proliferation, making it valuable for studying immune checkpoint inhibition. Commonly applied in preclinical models to evaluate antitumor efficacy and improve response to other immunotherapies. Also used in assays to measure cytokine production and immune cell signaling changes upon BTLA pathway modulation.