Schematic of the treatment of a patient with chimeric antigen receptor (CAR) T cells. (1) Isolation of peripheral T cells from patient via apheresis. (2) Transfection of T cells with a lentivirus containing genes for CAR directed against the tumor target antigen: binding of virus to T-cell membrane, fusion of virus with cell membrane, reverse transcription, DNA integration, and transcription/protein expression of CAR genes, and insertion of CAR into cell membrane. (3) Adoptive transfer of autologous CAR-T cells via infusion with or without prior lymphodepleting conditioning. (4) Patient monitoring for treatment response, and for persistence of CAR-T cells. Professional illustration by A. Y. Chen.