Furthermore, pre-treatment with an MMP-9 specific inhibitor (CAS 1177749-58-4) blocked the capacity of Wnt5a to enhance the invasiveness of CLL cells, indicating that MMP-9 plays a crucial role in Wnt5a/ROR1-enhanced CLL cell invasion (Fig. 3C). Here, ROR1 is linked to B-cell chronic lymphocytic leukemia.