When considering the anti-CD44 mAbs in preclinical or clinical development as cancer therapies [189,218,219], the humanized anti-CD44v6 mAb RG7356 has been shown to induce the in vitro caspase-dependent death of ZAP-70+ CLL cells from patients with a poor prognosis [188] (Table 2). Here, ZAP70 is linked to B-cell chronic lymphocytic leukemia.