CD28 and cancer: In addition, synthetic CLDN18.2-PD1/CD28 CAR-T cells (CT-001) expressing an antigen-binding domain that specifically binds to CLDN18.2 and a switch molecule containing the extracellular domain of the PD-1 receptor and the intracellular domain of the CD28 receptor, have excellent cytotoxicity specifically against CLDN18.2 positive cancer cells.