LY2109761 is primarily used in research settings to study the TGF-β signaling pathway, which plays a critical role in various cellular processes, including cell growth, differentiation, and apoptosis. It is a potent inhibitor of TGF-β receptor type I kinase, making it a valuable tool for investigating the effects of TGF-β signaling in cancer biology. Researchers utilize LY2109761 to explore its potential in inhibiting tumor progression and metastasis, particularly in cancers where TGF-β signaling is dysregulated. Additionally, it is employed in studies focusing on fibrosis, as TGF-β is a key mediator in fibrotic diseases. By blocking this pathway, LY2109761 helps scientists understand the mechanisms underlying these conditions and assess its therapeutic potential.