MUC1 and neoplasm: Their results demonstrated that CAR T cells engineered with the 5E5 antibody, a monoclonal antibody specifically designed to target the Tn antigen on MUC1—a tumor-associated form of the MUC1 protein often abnormally glycosylated in cancers—effectively eliminated Tn-MUC1-positive ICC (intrahepatic cholangiocarcinoma) cells in both in vitro and in vivo experiments.