CARS1 and infection: Due to differences in transduction efficiency between CARs B1 and B2, and to achieve similar expression in human primary T cells, we transduced CAR B1 at multiplicity of infection (MOI) 40, and CAR B2 at MOI 10 (Figure 1B), and reproducibly achieved similar percentage of ~80% CAR expression in T cells from four different healthy donors, whereas the MFI was somewhat higher in B2 CAR transductions, despite the lower MOI of lentiviral vector used (p<0.01), (Figure 1C).