Temsirolimus is a medication primarily used to treat advanced renal cell carcinoma, a type of kidney cancer. It belongs to a class of drugs known as mTOR inhibitors, which work by blocking a specific protein that helps cancer cells grow and divide. By inhibiting this protein, Temsirolimus can slow down the progression of the disease and improve patient outcomes. This drug is typically administered through an intravenous infusion and is often used in combination with other treatments. Patients receiving Temsirolimus may experience side effects such as fatigue, nausea, and increased risk of infections, so close monitoring by healthcare professionals is essential.