CASP8 and head and neck squamous cell carcinoma: Specifically, in HNSCC with no LNM (Tu−met), patients with high levels of both DR5 and caspase-8 had better overall survival and disease-free survival relative to patients with low levels of both DR5 and caspase-8 (P<0.0001 and P = 0.0124, respectively) (Fig. 6A).