CASP8 and pharyngeal squamous cell carcinoma: Moreover, the recent study reported that the somatic mutation of CASP8, a gene regulating apoptosis, only took place in oral squamous cell carcinoma, but almost not in pharyngeal squamous cell carcinoma [34], which was confirmed by the higher IWHMB of APOPTOSIS in oral squamous cell carcinoma than that in pharyngeal squamous cell carcinoma.