These findings were not restricted to mouse CAR-T cells as human E3K CAR-T cells were specifically activated in response to wild-type mouse embryonic fibroblasts (MEFs) but not by endosialin– CAL-51 tumor cells ectopically expressing human endosialin, nor by Cd248KO MEFs or vector-alone transfected CAL-51 cells (online supplemental figure 4). This evidence concerns the gene CD248 and neoplasm.