Another phase I trial using ascites-derived exosomes (AEXs) combined with GM-CSF for colorectal cancer patients demonstrated strong anti-tumor cytotoxic T-lymphocyte (CTL) responses against the carcinoembryonic antigen (CEA), a colorectal cancer biomarker, indicating that exosome-based vaccines could stimulate targeted immune responses [148]. This evidence concerns the gene CEACAM5 and colorectal cancer.