TGM3 and head and neck squamous cell carcinoma: The reduced protein level of full-length PARP, procaspase-3, procaspase-8 and Bcl-2 and the increased protein level of cleaved PARP and Bax in the TGM3-expressing HNSCC cell lines, as shown by western blot analysis, confirmed that the induction of apoptosis is closely involved in the effects of ectopic TGM3 expression.