that regulate monocyte-endothelial interactions in models of atherogenesis. They are interested in the structure and function of these molecules, and their importance in disease models. Finally, they have shown that leukocytes can effectively navigate through complex chemoattractant arrays, and they are exploring the mechanisms that permit this surprising behavior through computer simulations of chemotactic behavior, and through experimental manipulation of the molecules and receptors involved. Recent Publications Sigmundsdottir H, Pan J, Debes GF, Alt C, Habtezion A, Soler D, Butcher EC "DCs metabolize sunlight-induced vitamin D3 to 'program' T cell attraction to the epidermal chemokine CCL27." Nat Immunol 2007 Staton TL, Habtezion A, Winslow MM, Sato T, Love PE, Butcher EC "CD8(+) recent thymic emigrants home to and efficiently repopulate the small intestine epithelium." Nat Immunol 2006 Zabel BA, Ohyama T, Zuniga L, Kim JY, Johnston B, Allen SJ, Guido DG, Handel TM, Butcher EC "Chemokine-like receptor 1 expression by macrophages in vivo: Regulation by TGF-beta and TLR ligands." Exp Hematol 2006; 34: 8: 1106-14 Sato T, Thorlacius H, Johnston B, Staton TL, Xiang W, Littman DR, Butcher EC "Role for CXCR6 in recruitment of activated CD8+ lymphocytes to inflamed liver." J Immunol 2005; 174: 1: 277-83 Butcher EC, "Innovation: Can cell systems biology rescue drug discovery?" Nat Rev Drug Discov 2005; 4: 6: 461-7 Debes GF, Arnold CN, Young AJ, Krautwald S, Lipp M, Hay JB, Butcher EC "Chemokine receptor CCR7 required for T lymphocyte exit from peripheral tissues." Nat Immunol 2005; 6: 9: 889-94 Reiss Y, Proudfoot AE, Power CA, Campbell JJ, Butcher EC "CC chemokine receptor (CCR)4 and the CCR10 ligand cutaneous T cell-attracting chemokine (CTACK) in lymphocyte trafficking to inflamed skin." J Exp Med 2001; 194: 10: 1541–1547 Kim CH, Rott L, Kunkel EJ, Genovese MC, Andrew DP, Wu L, Butcher EC "Rules of chemokine receptor association with T cell polarization in vivo." J Clin Invest 2001; 108: 9: 1331–1339 Campbell DJ, Kim CH, Butcher EC "Separable effector T cell populations specialized for B cell help or tissue inflammation." Nat Immunol 2001; 2: 9: 876-81 Arnold CN, Campbell DJ, Lipp M, Butcher EC "The germinal center response is impaired in the absence of T cell-expressed CXCR5." Eur J Immunol 2007; 37: 1: 100-9 Kalesnikoff J, Rios EJ, Chen CC, Nakae S, Zabel BA, Butcher EC, Tsai M, Tam SY, Galli SJ "RabGEF1 regulates stem cell factor/c-Kit-mediated signaling events and biological responses in mast cells." Proc Natl