TNF and plasma cell myeloma: Inhibition of the IAPs in tumor cells is predicted to result in increased sensitivity to TNF-mediated cell death by switching TNFα signaling from activation of the classical NF-κB pathway towards caspase-8 mediated apoptosis (21, 22), and we have observed that TAC T cell produce large amounts of TNFα upon stimulation by myeloma cell lines (Figure 5C).