45. Larochelle A, Vormoor J, Hanenberg H, Wang JCY, Bhatia M, et al. (1996) Identification of primitive human hematopoietic cells capable of repopulating NOD/SCID mouse bone marrow: Implications for gene therapy. Nat Med 2: 1329–1337. 46. Hayashi Y, Furue MK, Okamoto T, Ohnuma K, Myoishi Y, et al. (2007) Integrins regulate mouse embryonic stem cell self-renewal. Stem Cells 25: 3005–3015. 47. Hayashi Y, Furue MK, Tanaka S, Hirose M, Wakisaka N, et al. (2010) BMP4 induction of trophoblast from mouse embryonic stem cells in defined culture conditions on laminin. In Vitro Cell Dev Biol Anim 46: 416–430. 48. Scholer HR, Ruppert S, Suzuki N, Chowdhury K, Gruss P (1990) New type of POU domain in germ line-specific protein Oct-4. Nature 344: 435–439. 49. Okamoto K, Okazawa H, Okuda A, Sakai M, Muramatsu M, et al. (1990) A novel octamer binding transcription factor is differentially expressed in mouse embryonic cells. Cell 60: 461–472. 50. Rosner MH, Vigano MA, Ozato K, Timmons PM, Poirie F, et al. (1990) A POU-domain transcription factor in early stem cells and germ cells of the mammalian embryo. Nature 345: 686–692. 51. Walker E, Ohishi M, Davey RE, Zhang W, Cassar PA, et al. (2007) Prediction and testing of novel transcriptional networks regulating embryonic stem cell self- renewal and commitment. Cell Stem Cell 1: 71–86. 52. Bernstine EG, Hooper ML, Grandchamp S, Ephrussi B (1973) Alkaline Phosphatase Activity in Mouse Teratoma. Proc Natl Acad Sci U S A 70: 3899–3903. 53. Auerbach W, Dunmore JH, Fairchild-Huntress V, Fang Q, Auerbach AB, et al. (2000) Establishment and chimera analysis of 129/SvEv- and C57BL/6-derived mouse embryonic stem cell lines. Biotechniques 29: 1024–1028, 1030, 1032. 54. Raz R, Lee CK, Cannizzaro LA, d’Eustachio P, Levy DE (1999) Essential role of STAT3 for embryonic stem cell pluripotency. Proc Natl Acad Sci U S A 96: 2846–2851. 55. Soprano DR, Blaner WS, eds (1994) Plasma retinol-binding protein. 2nd ed. New York: Raven Press Ltd. pp 257–281. 56. Bottenstein JE, Sato GH (1979) Growth of a rat neuroblastoma cell line in serum-free supplemented medium. Proc Natl Acad Sci U S A 76: 514–517. 57. Brewer GJ, Torricelli JR, Evege EK, Price PJ (1993) Optimized survival of hippocampal neurons in B27-supplemented Neurobasal, a new serum-free medium combination. J Neurosci Res 35: 567–576. 58. Cartwright P, McLean C, Sheppard A, Rivett D, Jones K, et al. (2005) LIF/ STAT3 controls ES cell self-renewal and pluripotency by a Myc-dependent mechanism. Development 132: 885–896. 59. Holliday MA (1999) Extracellular fluid and its proteins: dehydration, shock, and recovery. Pediatr Nephrol 13: 989–995. 60. Hewlett G (1991) Strategies for optimising serum-free media. Cytotechnology 5: 3–14. 61. Sato GH, Sato JD, Okamoto T, McKeehan WL, Barnes DW (2010) Tissue culture: the unlimited potential. In Vitro Cell Dev Biol Anim 46: 590–594. 62. Sato GH (1975) The role of serum in cell culture. In: Litwack G, ed. Biochemical Actions of Hormones. New York: Academic Press. pp 391–396. 63. Lawrenz B, Schiller H, Willbold E, Ruediger M, Muhs A, et al. (2004) Highly sensitive biosafety model for stem-cell-derived grafts. Cytotherapy 6: 212–222. 64. Wu D, Pan W (2010) GSK3: a multifaceted kinase in Wnt signaling. Trends in Biochemical Sciences 35: 161–168. 65. Doble BW, Woodgett JR (2003) GSK-3: tricks of the trade for a multi-tasking kinase. J Cell Sci 116: 1175–1186. 66. Jope RS, Johnson GV (2004) The glamour and gloom of glycogen synthase kinase-3. Trends Biochem Sci 29: 95–102. 67. Watanabe S, Umehara H, Murayama K, Okabe M, Kimura T, et al. (2006) Activation of Akt signaling is sufficient to maintain pluripotency in mouse and primate embryonic stem cells. Oncogene 25: 2697–2707. 68. Paling NR, Wheadon H, Bone HK, Welham MJ (2004) Regulation of embryonic stem cell self-renewal by phosphoinositide 3-kinase-dependent signaling. J Biol Chem 279: 48063–48070. Gsk3b Inhibition Induces Teratoma Formation 69. Itasaki N, Hoppler S (2010) Crosstalk between Wnt and bone morphogenic protein signaling: a turbulent relationship. Dev Dyn 239: 16–33. 70. Zhang W, Zhao Y, Tong C, Wang G, Wang B, et al. (2005) Hedgehog-regulated Costal2-kinase complexes control phosphorylation and proteolytic processing of Cubitus interruptus. Dev Cell 8: 267–278. 71. Riobo NA, Lu K, Ai X, Haines GM, Emerson CP, Jr. (2006) Phosphoinositide 3-kinase and Akt are essential for Sonic Hedgehog signaling. Proc Natl Acad Sci U S A 103: 4505–4510. 72. Kim WY, Wang X, Wu Y, Doble BW, Patel S, et al. (2009) GSK-3 is a master regulator of neural progenitor homeostasis. Nat Neurosci 12: 1390–1397. 73. Matsuda T, Nakamura T, Nakao K, Arai T, Katsuki M, et al. (1999) STAT3 activation is sufficient to maintain an undifferentiated state of mouse embryonic stem cells. Embo J 18: 4261–4269. 74. Niwa H, Burdon T, Chambers I, Smith A (1998) Self-renewal of pluripotent embryonic stem cells is mediated via activation of STAT3. Genes Dev 12: 2048–2060. 75. Chowdhury F, Li Y, Poh Y-C, Yokohama-Tamaki T, Wang N, et al. (2010) Soft Substrates Promote Homogeneous Self-Renewal of Embryonic Stem Cells via Downregulating Cell-Matrix Tractions. PLoS ONE 5: e15655. 76. He TC, Sparks AB, Rago C, Hermeking H, Zawel L, et al. (1998) Identification of c-MYC as a target of the APC pathway. Science 281: 1509–1512. 77. Nakagawa M, Takizawa N, Narita M, Ichisaka T, Yamanaka S (2010) Promotion of direct reprogramming by transformation-deficient Myc. Proc Natl Acad Sci U S A 107: 14152–14157. 78. Okita K, Ichisaka T, Yamanaka S (2007) Generation of germline-competent induced pluripotent stem cells. Nature 448: 313–317. 79. Nagy A, Rossant J, Nagy R, Abramow-Newerly W, Roder J (1993) Derivation of Completely Cell Culture-Derived Mice from Early-Passage Embryonic Stem Cells. PNAS 90: 8424–8428. 80. Viswanathan S, Benatar T, Mileikovsky M, Lauffenburger DA, Nagy A, et al. (2003) Supplementation-dependent differences in the rates of embryonic stem cell self-renewal, differentiation, and apoptosis. Biotechnol Bioeng 84: 505–517. 81. Tompers DM, Labosky PA (2004) Electroporation of Murine Embryonic Stem Cells: A Step-by-Step Guide. Stem Cells 22: 243–249. 82. Tanaka TS, Lopez de Silanes I, Sharova LV, Akutsu H, Yoshikawa T, et al. (2006) Esg1, expressed exclusively in preimplantation embryos, germline, and embryonic stem cells, is a putative RNA-binding protein with broad RNA targets. Dev Growth Differ 48: 381–390. 83. Tanaka TS, Davey RE, Lan Q, Zandstra PW, Stanford WL (2008) Development of a gene trap vector with a highly-sensitive fluorescent protein reporter system aiming for the real-time single cell expression profiling. Genesis 46: 347–356. 84. Ying QL, Smith AG (2003) Defined conditions for neural commitment and differentiation. Methods Enzymol 365: 327–341. 85. Tanaka TS, Nishiumi F, Komiya T, Ikenishi K (2010) Characterization of the 38 kDa protein lacking in gastrula-arrested mutant Xenopus embryos. Int J Dev Biol 54: 1347–1353. 86. Nichols J, Zevnik B, Anastassiadis K, Niwa H, Klewe-Nebenius D, et al. (1998) Formation of pluripotent stem cells in the mammalian embryo depends on the POU transcription factor Oct4. Cell 95: 379–391. 87. Tanaka TS, Kunath T, Kimber WL, Jaradat SA, Stagg CA, et al. (2002) Gene expression profiling of embryo-derived stem cells reveals candidate genes associated with pluripotency and lineage specificity. Genome Res 12: 1921–1928. 88. Masui S, Nakatake Y, Toyooka Y, Shimosato D, Yagi R, et al. (2007) Pluripotency governed by Sox2 via regulation of Oct3/4 expression in mouse embryonic stem cells. Nat Cell Biol 9: 625–635. 89. Takahashi K, Yamanaka S (2006) Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell 126: 663–676. PLoS ONE | www.plosone.org 10 June 2011 | Volume 6 | Issue 6 | e21355