Umirolimus is primarily used in the medical field, particularly in the development of drug-eluting stents. These stents are implanted in patients with coronary artery disease to keep the arteries open and improve blood flow. The chemical is coated onto the stent, where it gradually releases to inhibit the proliferation of smooth muscle cells, reducing the risk of restenosis (re-narrowing of the artery). This application is critical in cardiovascular interventions, enhancing the long-term effectiveness of stent procedures and improving patient outcomes.