SECTM1 CAR T cells lysed tumor cells in a CD7-dependent manner. (A) CD7 expression of K562 CD7 and control cells were detected by flow cytometry. (B) The cytotoxicity of SECTM1 CAR T cells toward K562 CD7 and control cells, percentage of dead cells were calculated. (C) IFNγ concentration in the coculture supernatant described in panel B was detected by ELISA. (D) CD7 expression in CD7-knockdown and shRNA control CCRF-CEM cells were detected by flow cytometry. (E) The cytotoxicity of SECTM1 CAR T cells toward control and shCD7 CCRF-CEM cells, percentage of dead cells were calculated by flow cytometry. (F) IFNγ released by the SECTM1 CAR T cells in the experiment described in panel E was detected by ELISA. Data in panels B, C, E, and F are presented as the mean ± SD of triplicates.