NF-AT-Jurkat is not a chemical but refers to a biological system involving the NF-AT (Nuclear Factor of Activated T-cells) signaling pathway in Jurkat cells, which are a well-known human T-lymphocyte cell line. This system is widely used in immunological research to study T-cell activation, signal transduction, and gene expression regulation. Its primary application lies in drug development and screening, particularly for immunosuppressive agents. Researchers use NF-AT-Jurkat assays to evaluate compounds that modulate T-cell receptor signaling, such as inhibitors of calcineurin, a key enzyme in NF-AT activation. These assays are instrumental in developing therapies for autoimmune diseases, organ transplant rejection, and chronic inflammation. The system is also employed in reporter gene assays, where Jurkat cells are engineered to express luciferase or GFP under the control of NF-AT response elements. This allows rapid, quantitative measurement of NF-AT activation in response to stimuli or drug candidates, making it a valuable tool in high-throughput screening environments.