CEACAM5 and colorectal carcinoma: The method of adoptive transfer of CAR-T cells that takes advantage of the cellular immune system against cancer has demonstrated impressive success in hematologic malignancies in particular of CD19 positive B cell malignancies, and it has been proposed for solid tumors like CRC, targeting surface proteins such as natural-killer group 2, member D (NKG2D), the ligands of which partially upregulate in tumor cells, and carcinoembryonic antigen (CEA) 21, 22.