Used in immunological research to study T-cell development and function, particularly in the context of pre-T-cell receptor signaling. The Fc tag enables easy detection and purification, and facilitates binding to Fc receptor-expressing cells for functional assays. Commonly applied in protein-protein interaction studies, ELISA, flow cytometry, and as a control in receptor-ligand binding experiments. Supports development of therapeutic antibodies and diagnostics by serving as a soluble recombinant antigen.