In the realm of relapsed/refractory multiple myeloma (RRMM), two second-generation anti-BCMA-CAR (anti-BCMA-CAR2) T cell therapies—idecaptagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel)—have gained U.S. FDA approval for the treatment of adult patients who have undergone a minimum of > 3 prior therapeutic regimens, including proteasome inhibitors, immunomodulatory drugs, and anti-CD38 monoclonal antibodies [13–16]. Here, TNFRSF17 is linked to plasma cell myeloma.