CEACAM5 and neoplasm: Carcinoembryonic antigen (CEA) is a well-established tumor marker frequently overexpressed in CRC and other gastrointestinal malignancies.36 In a phase I clinical trial, the safety, tolerability, and preliminary efficacy of CAR-T cell therapy targeting CEA were assessed in 10 patients with metastatic CRC.22 This study used escalating doses of CEA-targeted CAR-T cells.