Used in immunological research to study plasmacytoid dendritic cell (pDC) regulation, particularly in type I interferon responses linked to autoimmune diseases and antiviral immunity. Serves as a target for therapeutic antibodies and ligand-binding studies due to its role in modulating immune activation, with BST2 (Bone Marrow Stromal Cell Antigen 2) as a specific ligand. The His Tag allows for easy detection and purification in recombinant protein applications, making it valuable in assay development, drug screening, ELISA, and protein-protein interaction studies.