To verify that NKG2D(bbz) CAR-T cells can recognize NKG2D ligands on tumor cells and have cytotoxic effects, A549, ABC1, MDA-MB-231, K562, MMIS and U266 cells were selected, and both the RTCA method (Figures 2A, B) and luciferase method (Figures 2C, D) were used. Here, KLRK1 is linked to neoplasm.