Dual-targeting BCMA-SLAMF7- and BCMA-FAP-CART cells overcomes the negative effects of BM-CAFs in vitro. (A) Representative flow plots of UTD, BCMA-CART-, BCMA-SLAMF7-CART-, and BCMA-FAP-CART cells. (B) UTD, BCMA-CART-, BCMA-SLAMF7-, or BCMA-FAP-CART cells were cocultured with luciferase⁺OPM-2 with BM-CAFs. At 24 hours, cytotoxicity was assessed by luminescence relative to controls (mean and standard error of the mean [SEM]; upper asterisks, BCMA-CART vs BCMA-FAP-CART cells; lower asterisks, BCMA-CART vs BCMA-SLAMF7-CART cells; *P < .05, **P < .005, ***P < .001, two-way analysis of variance [ANOVA]; n = 2, two replicates). (C) BCMA-, BCMA-SLAMF7-, or BCMA-FAP-CART cells were cocultured with irradiated MM1.S for 5 days with BM-CAFs (mean and SEM; *P < .05, ****P < .0001, one-way ANOVA; n = 3, two replicates). (D) BCMA-, BCMA-SLAMF7-, or BCMA-FAP-CART cells were cocultured with MM1.S for 4 hours with BM-CAFs (mean and SEM; *P < .05, **P < .005, ****P < .0001, one-way ANOVA; n = 3, two replicates). (E) BCMA-, BCMA-SLAMF7-, or BCMA-FAP-CART cells or UTD were cocultured with irradiated MM1.S for 3 days with BM-CAFs, and supernatants were analyzed via multiplex (n = 2, two replicates). E:T, effector-to-target ratio; FITC, fluorescein isothiocyanate; GM-CSF, granulocyte macrophage colony-stimulating factor; IFN-γ, interferon-γ; n.s., not significant; sCD40L, soluble CD40 ligand; TNF, tumor necrosis factor.