Lenalidomide is an immunomodulatory agent with multiple mechanisms of action wich include antiproliferative activity as well as microenvironmental effects such as inhibition angiogenesis and stimulation of T-cell mediated response. Lenalidomide given as monotherapy proved to be active, with an acceptable toxicity profile, in B-cell malignancies such as multiple myeloma, chronic lymphocytic leukemia, mantle cell lymphoma and diffuse large B-cell lymphoma.