CASP8 and neoplasm: Interestingly, birinapant enhanced sensitivity to radiation only under Casp8 knockdown (with an REF of 0.5 for the control vs. 2.3 for the shCasp8 mouse cohorts), with mice bearing shCasp8 MOC1 tumors demonstrating a significant increase in tumor growth delay and a significantly improved survival when compared with those bearing matching control tumors (Figure 6, A and B; Table 1; and Supplemental Tables 7–9).