Organ transplantation has revolutionised medical treatment, offering hope and improved quality of life to countless individuals with organ failure. However, the success of organ transplantation hinges on the body's acceptance of the new organ, a process that can be complicated by rejection. Sirolimus, a medication commonly used in transplant medicine, plays a crucial role in preventing organ rejection. But how does sirolimus achieve this? Let's explore the mechanisms behind sirolimus's ability to prevent organ rejection and its significance in transplantation medicine.