Importantly, we show upregulation of death receptor 5 (DR5) in PBOX-15-treated myeloma cells, with resultant potentiation of apoptosis following cotreatment with PBOX-15 and the DR5 ligand, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). This evidence concerns the gene TNFRSF10B and plasma cell myeloma.