Used primarily in the treatment of multiple myeloma, lenalidomide is also effective for myelodysplastic syndromes, especially those with deletion 5q abnormality. It modulates the immune system, inhibits tumor angiogenesis, and promotes cancer cell death. Commonly used in combination with dexamethasone for multiple myeloma patients. Also indicated for mantle cell lymphoma in certain cases. Its immunomodulatory properties make it useful in managing symptoms and delaying disease progression. Requires strict risk evaluation and mitigation strategies due to high risk of severe birth defects.