Rather, we found that the HPV(−) HNSCC cell lines harboring both FADD and BIRC2 amplification and overexpression were more sensitive to birinapant in combination with TNF-α or TRAIL in vitro, as well as in animal models in vivo when combined with radiation, which induces death ligand expression23. This evidence concerns the gene FADD and head and neck squamous cell carcinoma.