Impaired SDF1-α-mediated migration of CLL cells upon lenalidomide treatment. A total of 1 × 10⁷ PBMC from CLL patients were cultured in 400 µL complete medium in 24-well plates in the presence or absence of 10 µM lenalidomide for 3 days. The, 3 × 10⁶ of these pretreated cells were seeded in the upper compartment of a transwell with 5 µm pore size. Complete medium containing 200 ng/mL SDF1-α was added to the lower compartment as chemoattractant. After 1.5 hours of incubation at 37°C, migrated cells were quantified using a ViCell counter. Mean values and SEM of 3 technical replicates of 1 representative example out of 3 independently performed experiments are shown.