CD19 and lymphoma: T cells from patients are transferred to the chimeric antigen receptor (CAR) gene and injected intravenously. CAR genes code anti-CD19 that binds to CD19, a B cell lymphoma antigen, 4-1BB (CD137) and CD3 zeta costimulatory domains. When CD19 and anti-CD19 bind, CD3 zeta costimulatory domains activate T cells, grow, obtain effector functions and release inflammatory cytokines and chemokines. 4-1BB promotes CAR T cell growth to remove CD19-positive cells.