TNFRSF13B and neoplasm: In vivo study further showed that when compared to CAR T cells targeting BCMA alone, ACAR-T cells could achieve continuous in vivo tumor suppression even in the event of BCMA downregulation [84] Thus, ACAR-T cells could represent an alternative strategy for the treatment of MM patients co-expressing BCMA and TACI but with BCMA expression downregulated or lost.