Cirmtuzumab, an anti-ROR1 mAb, has demonstrated to be well tolerated and effective at inhibiting ROR1 signaling in a phase I study enrolling patients with progressive, refractory, and relapsed CLL (229), and is currently under evaluation for its safety and efficacy when given in combination with ibrutinib in patients with B-cell lymphoid malignancies in a phase Ib/II protocol (NCT03088878). Here, ROR1 is linked to B-cell chronic lymphocytic leukemia.