CEACAM5 and neoplasm: To recapitulate the in vitro observations in animal tumor model, we inoculated mice with MC32-CEA tumor cells (1 × 106 cells per mouse) subcutaneously in the right lateral flank, followed by intravenous injection of WT or eEF-2K KO CEA-specific CAR-T cells (5 × 106 cells per mouse) (Fig. 5E).