Used in immunosuppressive research to study T-cell activation and immune response modulation. Employed in pharmaceutical development for organ transplant models due to its ability to inhibit calcineurin, a key enzyme in immune signaling. Also utilized in cancer research for its potential to reverse multidrug resistance in tumor cells by inhibiting P-glycoprotein efflux pumps. Commonly applied in in vitro studies requiring selective immunosuppression or investigation of cellular transport mechanisms.