CST6 and neoplasm: To evaluate the in vivo anti-tumor activity and anti–bone resorption of BCMA–CST6–CAR-T cells, we injected MM1.S, OPM2, or H929 cells expressing luciferase into NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice.