Used in immunological research to study natural killer (NK) cell activation and immune responses. Serves as a ligand for the NKG2D receptor, making it valuable in assays that examine cell signaling, cytotoxicity, and immune surveillance. The His tag allows for easy purification and detection, facilitating its use in protein-protein interaction studies, ELISA, and flow cytometry. Commonly employed in cancer immunotherapy research due to its role in stress-induced immune recognition.