CEACAM5 and neoplasm: As such, we have designed TCEs to target CEA (Figures 1A, B; Supplementary Figure 1A), a cell surface protein abundantly expressed on colorectal tumour cells, especially after treatment with standard of care 5-FU chemotherapy (Supplementary Figure 2E), or the FAP antigen, expressed on CAF populations, as a two-pronged immunostimulatory attack on CRCs to overcome tumour heterogeneity and stromal barriers in the TME of CRC, respectively.