The α-globin super-enhancer acts in an orientation-dependent manner by Kassouf, MT, Francis, HS, Gosden, M, Suciu, MC, Downes, DJ, Harrold, C, Larke, M, Oudelaar, M, Cornell, L, Blayney, J, Telenius, J, Xella, B, Shen, Y, Sousos, N, Sharpe, JA, Sloane-Stanley, J, Smith, AJH, Babbs, C, Hughes, JR, Higgs, DR