In addition, in the tumor specimens from the mice receiving the WT CEA CAR CD8+ T cells, an increase in Ki-67− macrophages (Ki-67−F4/80+) was detected, whereas the tumor specimens from the mice receiving eEF-2K KO CAR-T cells had high amounts of Ki-67+ macrophages (Ki-67+F4/80+) (Fig. 6, I and J), another difference in the antitumor efficacy between the WT CEA CAR-T cells and eEF-2K KO CEA-specific CAR-T cells. This evidence concerns the gene CEACAM5 and neoplasm.