The structure of a chimeric antigen receptor (CAR) consists of a single-chain variable fragment derived from a monoclonal antibody targeting a cancer-specific antigen, intracellular segment, signaling domain derived from T-cell receptor (TCR), and one or more co-stimulatory sequences (CD28, OX40 or 4-1BB) [54]. The gene discussed is TNFRSF9; the disease is cancer.