Ubiquitous heterogeneity and asymmetry of the chromatin environment at regulatory elements - Kundaje, Anshul; Kyriazopoulou-Panagiotopoulou, Sofia; Libbrecht, Max; Smith, Cheryl L.; Raha, Debasish; Winters, Elliott E.; Johnson, Steven M.; Snyder, Michael; Batzoglou, Serafim; Sidow, Arend (Genome Research, 2012)