Calcineurin substrate is widely used in biochemical research to study the activity of calcineurin, a calcium-dependent phosphatase enzyme. It plays a crucial role in understanding cellular signaling pathways, particularly those involving calcium and immune responses. Researchers utilize this substrate to monitor and quantify calcineurin activity in various experimental setups, such as enzyme assays and drug screening. It is especially valuable in investigating immunosuppressive mechanisms, as calcineurin is a target of drugs like cyclosporine and tacrolimus. Additionally, it aids in exploring neurodegenerative diseases, cardiac hypertrophy, and T-cell activation processes, providing insights into therapeutic interventions.