FADD and head and neck squamous cell carcinoma: Nevertheless, HNSCC is associated with mutations in genes such as cIAP1 [18]/BIRC2 [19], caspase-8 [20], FADD [19], and TNF [21] that affect the extrinsic apoptosis pathway indicating that this is pathway is likely to be particularly relevant when exploring SM induced cell death in HNSCC.