Lenalidomide and pomalidomide induce development of granulocytic progenitors. Purified CD34⁺ cells were cultured with increasing concentrations of thalidomide, pomalidomide, lenalidomide, or 0.1% DMSO as vehicle control. (A) Erythroid colonies (burst-forming units-erythroid/CFU-erythroid) and (B) myeloid colonies (CFU-G, CFU-GM, and CFU-GEMM) were evaluated as described in “Colony-forming assay.” (C) Bone marrow mononuclear cells from healthy donors and MM patients were cultured with lenalidomide (left panel), pomalidomide (right panel), or DMSO as described in “Colony-forming assay.” Results are shown as mean ± SD from triplicates. *P ≤ .001. **P ≤ .01. ***P ≤ .05.