CD4 and plasma cell myeloma: High throughput screening of 351 different cytokines and immune proteins in the supernatants of the T cells cultures revealed strong upregulation of IL-6, IL-8, both vital survival factors for myeloma cells [46–48], and CXCL5, a chemokine that could enhance the frequency of CD4 Treg [49], in the cultures containing CD8+SLAMF7+ cells.