224 A. Jögi et al. breast cancer cells. Proc Natl Acad Sci USA. 2003;100: 3983–8. 28. Mani SA, Guo W, Liao MJ, Eaton EN, Ayyanan A, Zhou AY, et al. The epithelial-mesenchymal transition generates cells with properties of stem cells. Cell. 2008;133: 704–15. 29. Haase VH. Oxygen regulates epithelial-to-mesenchymal tran- sition: insights into molecular mechanisms and relevance to disease. Kidney Int. 2009;76:492–9. 30. Hoehner JC, Gestblom C, Hedborg F, Sandstedt B, Olsen L, Påhlman S. A developmental model of neuroblastoma: dif- ferentiating stroma-poor tumors’ progress along an extra- adrenal chromafﬁn lineage. Lab Invest. 1996;75:659–75. 31. Odelstad L, Pahlman S, Nilsson K, Larsson E, Lackgren G, Johansson KE, et al. Neuron-speciﬁc enolase in relation to differentiation in human neuroblastoma. Brain Res. 1981;224: 69–82. 32. Piccirillo SG, Reynolds BA, Zanetti N, Lamorte G, Binda E, Broggi G, et al. Bone morphogenetic proteins inhibit the tumorigenic potential of human brain tumour-initiating cells. Nature. 2006;444:761–5. 33. Lee J, Son MJ, Woolard K, Donin NM, Li A, Cheng CH, et al. Epigenetic-mediated dysfunction of the bone morphogenetic protein pathway inhibits differentia- tion of glioblastoma-initiating cells. Cancer Cell. 2008;13: 69–80.