Used in biomedical research to quantify B7-H4 protein levels in biological samples such as serum, plasma, and cell culture supernatants. Enables study of immune regulation, particularly in cancer immunology, where B7-H4 modulates T-cell activity. Supports investigation into autoimmune diseases, tumor immune evasion, and therapeutic response monitoring. Provides a reliable, sensitive method for detecting soluble B7-H4 in clinical and preclinical studies.