CD248 and neoplasm: Similarly, in C57BL/6 mouse E3K CAR-T cell cytotoxicity assays, 10T1/2 and MRC-5 cell viability was significantly reduced at effector:target ratios of 5:1 or 10:1 compared with 10T1/2 and MRC-5 cells co-cultured with Mock-T cells or when E3K CAR-T cells were co-cultured with endosialin– human MCF7 (figure 2D, lower panels) or mouse 4T1 (online supplemental figure 3B) tumor cells.