The hematoxylin and eosin (H&E) staining of the tumor specimens showed that there were considerably greater amounts of tumor cells in the xenografts from the mice treated with the CEA-specific eEF-2K KO CAR-T cells than in the xenografts from the mice receiving the WT CEA CD8+ CAR-T cells (Fig. 6H). Here, CEACAM5 is linked to neoplasm.