ARHGEF1 and leukemia: To this end, we found that the capacity of Wnt5a to induce ROR1 to interact and activate cortactin, recruit and activate ARHGEF1, and enhance leukemia-cell migration could be blocked by cirmtuzumab, a first-in-class humanized anti-ROR1 mAb, which is being evaluated in patients with CLL (https://clinicaltrials.gov/ct2/show/NCT02222688) [39, 40].