Comment on

• IDO expression by dendritic cells: tolerance and tryptophan catabolism.

  Mellor AL, Munn DH. Mellor AL, et al. Nat Rev Immunol. 2004 Oct;4(10):762-74. doi: 10.1038/nri1457. Nat Rev Immunol. 2004. PMID: 15459668 Review.
• Reciprocal TH17 and regulatory T cell differentiation mediated by retinoic acid.

  Mucida D, Park Y, Kim G, Turovskaya O, Scott I, Kronenberg M, Cheroutre H. Mucida D, et al. Science. 2007 Jul 13;317(5835):256-60. doi: 10.1126/science.1145697. Epub 2007 Jun 14. Science. 2007. PMID: 17569825
• Induction of regulatory T cells by physiological level estrogen.

  Tai P, Wang J, Jin H, Song X, Yan J, Kang Y, Zhao L, An X, Du X, Chen X, Wang S, Xia G, Wang B. Tai P, et al. J Cell Physiol. 2008 Feb;214(2):456-64. doi: 10.1002/jcp.21221. J Cell Physiol. 2008. PMID: 17654501
• Control of T(reg) and T(H)17 cell differentiation by the aryl hydrocarbon receptor.

  Quintana FJ, Basso AS, Iglesias AH, Korn T, Farez MF, Bettelli E, Caccamo M, Oukka M, Weiner HL. Quintana FJ, et al. Nature. 2008 May 1;453(7191):65-71. doi: 10.1038/nature06880. Epub 2008 Mar 23. Nature. 2008. PMID: 18362915
• Transforming growth factor-beta 'reprograms' the differentiation of T helper 2 cells and promotes an interleukin 9-producing subset.

  Veldhoen M, Uyttenhove C, van Snick J, Helmby H, Westendorf A, Buer J, Martin B, Wilhelm C, Stockinger B. Veldhoen M, et al. Nat Immunol. 2008 Dec;9(12):1341-6. doi: 10.1038/ni.1659. Epub 2008 Oct 19. Nat Immunol. 2008. PMID: 18931678
• An endogenous tumour-promoting ligand of the human aryl hydrocarbon receptor.

  Opitz CA, Litzenburger UM, Sahm F, Ott M, Tritschler I, Trump S, Schumacher T, Jestaedt L, Schrenk D, Weller M, Jugold M, Guillemin GJ, Miller CL, Lutz C, Radlwimmer B, Lehmann I, von Deimling A, Wick W, Platten M. Opitz CA, et al. Nature. 2011 Oct 5;478(7368):197-203. doi: 10.1038/nature10491. Nature. 2011. PMID: 21976023