In this report, three stressors have been utilized: tunicamycin, an inhibitor of GlcNAc phosphotransferase, causes a significant accumulation of unfolded proteins, activates the UPR, increases Txndc5, and ultimately results in cell death by apoptosis in human head-and-neck carcinoma cells [36]. This evidence concerns the gene GNPTAB and head and neck carcinoma.