This double-negative tumor population was not observed in significant numbers in untreated animals or animals treated with single-input CS1 CAR-T cells (Luc90 Short and huLuc63 Long; Fig. 4c, Supplementary Fig. 13a), underscoring BCMA’s particular vulnerability to antigen escape when treated with single-input BCMA CAR-T cells. Here, TNFRSF17 is linked to neoplasm.