Lenalidomide induces G-CSF and G-CSF receptor expression. Purified CD34⁺ cells were treated with 0.1% DMSO (control), pomalidomide, or lenalidomide. (A) Supernatants of CD34⁺ cells treated with pomalidomide, lenalidomide, or 0.1% DMSO were analyzed for cytokine secretion (pg/mL) after 1, 3, and 6 days. Black bars represent control; gray bars, lenalidomide treatment. Intra-assay variability, expressed as coefficient of variation (CV = SD divided by the mean) was calculated based on determining quadruplicates of standards. The SD was calculated based on quadruplicates and was less than 10%. (B-C) CD34⁺ cells were analyzed for G-CSF receptor protein expression by Western blot. β-Actin served as loading control.