To assess the antitumor specificity, we co-cultured CAR-Ms with GD2− allogeneic healthy cells: arterial endothelial cells (AEC-NOS3-NanoLuc-2A-tdTomato) and smooth muscle cells (SMC-MYH11-NanoLuc-2A-tdTomato), as well as GD2− tumor cells: Raji-AkaLuc-GFP and K562-AkaLuc-GFP (Figures 4F and 4G). Here, MYH11 is linked to neoplasm.