Schematic representation of potential T-cell activation by anti-HSP–directed humoral immune responses. In the context of immunogenic cell death, HSPs are secreted or translocated to the cell surface and serve as DAMPs. Such DAMPs can recruit and activate DCs directly as shown on the right. Opsonization of HSPs by the antibody immune response may even enhance this DC activation by interaction of immune complexes with the Fcγ receptor (left part). Both ways may result in engulfment of DAMPs and potent tumor antigen presentation to T cells, potentially leading to effective T-cell–mediated antimyeloma immune responses. CTL, cytotoxic T-lymphocytes. Diagram adapted from Kroemer et al.⁶²