Used in biomedical research to quantify levels of STAT4 protein in cell lysates, tissue extracts, or biological fluids such as serum and plasma. Enables researchers to study the activation and regulation of the JAK-STAT signaling pathway, particularly in immune responses. Widely applied in studies related to autoimmune diseases like rheumatoid arthritis, lupus, and inflammatory bowel disease, where STAT4 plays a key role in mediating cytokine signaling, especially in response to interleukin-12 (IL-12). Supports investigation into T-cell differentiation, particularly Th1 cell development, and helps assess the efficacy of therapeutic agents targeting inflammatory pathways. Commonly used in preclinical research and drug development to monitor biomarker expression and signaling dynamics.