SDC1 and smoldering plasma cell myeloma: Heteroclitic peptides derived from XBP1 (X-box-binding protein 1), CD138 (syndecan-1), and CS1 were shown alone or in combination to induce the expansion of myeloma-specific T cells with the capacity to lyse tumor cells.72–75 A trial is currently underway in which patients with smoldering myeloma undergo vaccination with combined myeloma-associated peptides in the context of immune adjuvant.