Cell surface expression of CXCR4 in NBC and CLL. NBC and CLL cells were cocultured with BMF+CpG/IL-15 and treated with DMSO, 0.4-μM ibr, or 0.2-μM ven for 96 hours. Surface CXCR4 expression was determined by flow cytometry. Expression of CXCR4 of each sample was normalized to that of FSCCL cell line, which was included as a standard in each run. Percentage of change is defined as drug-DMSO/DMSO × 100%.