Used in immunological research to study T-cell activation and co-stimulatory signaling pathways. Functions as a soluble receptor fusion protein that binds to ICOS ligand, enabling investigation of immune regulation in autoimmune diseases, cancer immunotherapy, and inflammatory conditions. Commonly employed in ELISA, surface plasmon resonance, and binding assays to quantify interactions with ligands or therapeutic antibodies. Also utilized in cell-based assays to modulate T-cell responses and evaluate checkpoint pathway modulation.