Used primarily in the treatment of multiple myeloma, lenalidomide is also effective in managing myelodysplastic syndromes, particularly those with deletion 5q abnormality. It modulates the immune system, inhibits angiogenesis, and promotes cancer cell death. Commonly prescribed in combination with dexamethasone for multiple myeloma patients, it helps delay disease progression and improve survival rates. It is also used in mantle cell lymphoma and other hematologic malignancies due to its immunomodulatory and anti-inflammatory properties. Treatment requires careful monitoring due to risks of severe birth defects and blood-related side effects.