Used in biomedical research to quantify levels of the Smad3 protein in cell lysates or tissue samples. Enables researchers to study TGF-β signaling pathway activity, which plays a key role in cell growth, differentiation, and apoptosis. Widely applied in studies related to fibrosis, cancer progression, immune regulation, and inflammatory diseases. Provides a reliable, sensitive, and high-throughput method for monitoring Smad3 activation in response to experimental treatments or disease states.