8 [78] S. Florian, K. Wingler, K. Schmehl et al., “Cellular and subcel- lular localization of gastrointestinal glutathione peroxidase in normal and malignant human intestinal tissue,” Free Radical Research, vol. 35, no. 6, pp. 655–663, 2001. [79] H. Mo¨rk, O. H. Al-Taie, K. Bahr et al., “Inverse mRNA expression of the selenocysteine-containing proteins GI-GPx and SeP in colorectal adenomas compared with adjacent normal mucosa,” Nutrition and Cancer, vol. 37, no. 1, pp. 108– 116, 2000. [80] M. M. Serewko, C. Popa, A. L. Dahler et al., “Alterations in gene expression and activity during squamous cell carcinoma development,” Cancer Research, vol. 62, no. 13, pp. 3759–3765, 2002. [81] M. Woenckhaus, L. Klein-Hitpass, U. Grepmeier et al., “Smoking and cancer-related gene expression in bronchial epithelium and non-small-cell lung cancers,” Journal of Pathol- ogy, vol. 210, no. 2, pp. 192–204, 2006. [82] R. S. Esworthy, L. Yang, P. H. Frankel, and F. F. Chu, “Epithelium-speciﬁc glutathione peroxidase, Gpx2, is involved in the prevention of intestinal inﬂammation in selenium- deﬁcient mice,” Journal of Nutrition, vol. 135, no. 4, pp. 740– 745, 2005. [83] J. Walshe, M. M. Serewko-Auret, N. Teakle et al., “Inactivation of glutathione peroxidase activity contributes to UV-induced squamous cell carcinoma formation,” Cancer Research, vol. 67, no. 10, pp. 4751–4758, 2007. [84] R. S. Esworthy, R. Aranda, M. G. Mart´ın, J. H. Binder, S. W. Doroshow, and F. F. Chu, “Mice with combined disruption of gpx1 and gpx2 genes have colitis,” American Journal of Physiology, vol. 281, no. 3, pp. G848–G855, 2001. [85] F. F. Chu, R. S. Esworthy, P. G. Chu et al., “Bacteria-induced intestinal cancer in mice with disrupted Gpx1 and Gpx2 genes,” Cancer Research, vol. 64, no. 3, pp. 962–968, 2004. [86] A. Banning, S. Florian, S. Deubel et al., “GPx2 counter- acts PGE2 production by dampening COX-2 and mPGES- 1 expression in human colon cancer cells,” Antioxidants and Redox Signaling, vol. 10, no. 9, pp. 1491–1500, 2008. [87] A. Banning, A. Kipp, S. Schmitmeier et al., “Glutathione peroxidase 2 inhibits cyclooxygenase-2-mediated migration and invasion of HT-29 adenocarcinoma cells but supports their growth as tumors in nude mice,” Cancer Research, vol. 68, no. 23, pp. 9746–9753, 2008. [88] S. Florian, S. Krehl, M. Loewinger et al., “Loss of GPx2 increases apoptosis, mitosis, and GPx1 expression in the intestine of mice,” Free Radical Biology and Medicine, vol. 49, no. 11, pp. 1694–1702, 2010. [89] W. J. Van Houdt, B. L. Emmink, T. V. Pham et al., “Compar- ative proteomics of colon cancer stem cells and diﬀerentiated tumor cells identiﬁes BIRC6 as a potential therapeutic target,” Molecular and Cellular Proteomics, vol. 10, no. 12, Article ID M111.011353, 2011. [90] W. Yan and X. Chen, “GPX2, a direct target of p63, inhibits oxidative stress-induced apoptosis in a p53-dependent man- ner,” The Journal of Biological Chemistry, vol. 281, no. 12, pp. 7856–7862, 2006. [91] A. Kipp, A. Banning, and R. Brigelius-Flohe´, “Activation of the glutathione peroxidase 2 (GPx2) promoter by β-catenin,” Biological Chemistry, vol. 388, no. 10, pp. 1027–1033, 2007. [92] S. Krehl, M. Loewinger, S. Florian et al., “Glutathione peroxidase-2 and selenium decreased inﬂammation and tumors in a mouse model of inﬂammation-associated carcino- genesis whereas sulforaphane eﬀects diﬀered with selenium supply,” Carcinogenesis, vol. 33, no. 3, pp. 620–628, 2012. International Journal of Cell Biology [93] H. Yang, X. Jia, X. Chen, C. S. Yang, and N. Li, “Time selective chemoprevention of vitamin E and selenium on esophageal carcinogenesis in rats: the possible role of nuclear factor kappaB signaling pathway,” International Journal of Cancer. In press.