KLRK1 and sarcoma: While the in vivo anti-tumor activity and treatment efficiency of DNAM-1+ or NKG2D+ GM NK-92 cells yet remains to be investigated in xenograft models of sarcoma, we and others have demonstrated that WT and GM NK-92 cells have the ability to exert potent anti-tumor responses both in pre-clinical animal models and clinical trials including various solid tumors (114–118) as well as several hematological malignancies (119–122).