Fig. 1.

A CAR T-cell structure: first-generation CARs contain an intracellular signaling domain of CD3 zeta chain alone; second-generation CARs includes a single co-stimulatory domain (CD28 or 4-1BB); third-generation CARs combine two of the co-stimulatory domains; fourth generation CARs with transgene to express cytokines [48]; bispecific/dual-CAR T cells: CAR T cells recognizing two targets simultaneously on target cells; split signal CARs: The two split structures of the CAR-T cell are assembled and activated in the presence of a specific particular molecule. B CAR T cells—the application in clinical practice