The preclinical study clarified that NKG2D-based CAR-T cells showed strong cytotoxicity against NKG2DL+ cell lines in vitro as well as a therapeutic effect against NKG2DL+ cell xenografts in vivo. In addition, the data also demonstrated the safety of NKG2D-based CAR-T therapy. NKG2D-based CART represent a potentially effective and safety therapeutic approach for patient with relapsed/refractory NKG2DL+ solid tumors. In this trial, the investigators researched the safety of administering NKG2D-based CAR-T which generated with CD8 hinge region and transmembrane region, 4-1BB costimulatory region and CD3 zeta region. The investigators also assessed that disease response was determined within the context of a phase I trial.