TNFRSF13B and neoplasm: When TACI antigen was knocked out, both bispecific CARs were initially able to clear tumor in vitro and in vivo, but both anti-BCMA and anti-BCMA–anti-TACI CARs eventually relapsed while anti-TACI–anti-BCMA CARs mediated sustained tumor clearance (Fig. 8d–f).