Used in immunological research to study the role of Dickkopf-1 (DKK1) in Wnt signaling pathways, particularly in models related to bone metabolism, cancer progression, and autoimmune diseases. The N256Q mutation enhances protein stability and solubility, making it suitable for in vitro assays and structural studies. The His tag allows for efficient purification and detection, facilitating use in ELISA, Western blotting, and protein-protein interaction experiments. Commonly employed in developing and validating anti-DKK1 therapeutic antibodies and in investigating placental biology and hemolytic disease of the newborn related to Rh signaling.