TAC1 and plasma cell myeloma: In addition, screening of multiple myeloma surface antigens has identified other promising targets, including CD28 (Tp44), CD48 (BLAST), CD74 (CLIP), CD138 (SDC1), CD229 (SLAMF3), CD319 (SLAMF7), CCR10 (GPR2), TAC1 (NPK), TXNDC11, SLC1A5 (AAAT) [36].