Concomitantly, surface expression of monoclonal immunoglobulin was decreased on IL-10 treated myeloma cells (NCI-H929, IgA myeloma; OPM-2, IgG myeloma) (Figure 6D), whereas we found higher levels of free immunoglobulin in the supernatants of these cells upon CCL27 +/− bortezomib treatment. Here, IL10 is linked to plasma cell myeloma.