BTK and B-cell chronic lymphocytic leukemia: Additionally, migration assays through Transwell, with CXCL12 chemokine as a chemo-attractive agent, showed how 5 μM of defactinib could reduce the migration/cell invasion of CLL cells; the combination of defactinib with the Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib (both drugs were used at 2.5 μM) had a synergistic effect in decreasing the migration of CLL cells compared with the use of the single agents (25).