We tested this combination in vivo using SMZ1 KLRG1+ subcutaneous xenografts in NSG mice. After 17 days of treatment, combination (mAb208 + Duv)- treated mice had a marked reduction in their mean tumor volumes (159 mm3) relative to mAb208 (1003 mm3 ; p=0.03), Duv (465.6 mm3 ; p=0.03) and CTL (2104 mm3 ; p=0.03) mice resulting in prolonged survival (Fig. 2).