CD37CAR expression in BL-41 does not mask CD37. (A) Flow cytometric analysis of BL-41 cells transduced with CD19CAR or CD37CAR. Expression of CD19 and CD37 was detected by commercial antibody clones or by the corresponding antibody clones from which the CAR constructs were derived. The expression of CARs was also validated by anti-mouse Fab and anti–c-Myc antibodies. Data from 1 of 2 experiments are shown. (B) BLI-based measurement of cytotoxicity mediated by mock T cells, CD19CAR T cells, or CD37CAR T cells when cocultured at an E:T ratio of 10:1 with target cells BL-41, BL-41 CD19CAR, or BL-41 CD37CAR. Lysis was analyzed after 1, 2, 3, 4.5, 7, and 9 hours of coculture. Data represent mean ± standard deviation of quadruplicates. Representative data from 1 of 3 experiments are shown. ****P < .0001, Student t test with Bonferroni correction between effector condition and its respective negative control.