CD248 and neoplasm: A preliminary study was then performed in 4T1 tumor-bearing or tumor-naive BALB/c mice, using the experimental timeline outlined in online supplemental figure 7B, with BALB/c E3K CAR or Mock-T cells injected 13 days after 4T1 cell inoculation when the tumors were small but had strong endosialin expression in the tumor stroma (figure 4A).