Used as a recombinant protein antigen in immunoassay development and antibody screening due to its His-tagged structure, enabling detection and purification. Commonly applied in immunological research to study immune checkpoint pathways, particularly in cancer immunotherapy. Supports binding assays and protein-protein interaction studies with receptors or ligands involved in T-cell regulation. Also utilized in vaccine development and therapeutic antibody production targeting the VISTA pathway to modulate immune responses.