This compound is not a chemical in the traditional sense but refers to a genetically engineered cell line—specifically, a modified Jurkat T-cell line expressing human LAG-3 and an NF-AT (nuclear factor of activated T-cells) reporter system. It is primarily used in immunological research and drug development. The main application lies in studying immune checkpoint pathways, particularly the LAG-3 (Lymphocyte-Activation Gene 3) receptor, which plays a critical role in downregulating T-cell activation. This cell line is used to screen and evaluate potential therapeutic agents such as blocking antibodies or small molecules targeting the LAG-3 pathway. Activation of LAG-3 in these cells leads to measurable NF-AT-driven reporter signals (e.g., luciferase or GFP), allowing quantitative assessment of T-cell inhibition or its reversal. It is widely used in high-throughput screening for cancer immunotherapies, especially in developing combination therapies with other checkpoint inhibitors like PD-1 or CTLA-4. The system provides a reproducible and sensitive platform for assessing the functional activity of biologics and small molecules in modulating T-cell responses.