LY 3200882 is a potent and selective antagonist of the TGF-β receptor type I kinase (ALK5). It is primarily used in research settings to study the role of the TGF-β signaling pathway in various biological processes and disease models. Due to its ability to inhibit TGF-β-mediated responses, it has been investigated for potential applications in fibrotic diseases, where excessive TGF-β activity leads to tissue scarring in organs such as the liver, lungs, and kidneys. It is also explored in oncology research, as TGF-β signaling can promote tumor progression and immune evasion. By blocking this pathway, LY 3200882 helps assess the therapeutic impact of ALK5 inhibition on tumor growth, metastasis, and the tumor microenvironment. Additionally, it serves as a tool compound in immunology to understand TGF-β’s role in regulating immune cell function and inflammation.