CXCR4 and B-cell chronic lymphocytic leukemia: Thus, we evaluated the effect of IQS019 on the migratory capacity of malignant B cells, using a CXCL12-dependent chemotaxis assay with 3 cell lines harboring detectable levels of CXCR4 (Additional file 1: Figure S3) and in a set of seven CLL primary samples, either untreated or pre-treated with IQS019 or with the standard CXCR4 antagonist AMD3100.