IMiDs exert their anti-neoplastic action by affecting various cancer cell functions and the microenvironment, including cytokine production, immune cell function, and in some instances, inflammation, cell proliferation and cell death. The IMiD thalidomide has been found to be effective as an anti-MM agent in one-third of myeloma patients; notably, higher response rates have been observed when combined with steroids. Lenalidomide is an analog of thalidomide that has shown more potent anti-MM activity than thalidomide in preclinical studies, and has been FDA-approved for the treatment of previously untreated as well as relapsed or refractory MM (RRMM) in combination with dexamethasone. Recently, an analog of thalidomide and lenalidomide, pomalidomide, has also been approved for RRMM patients.