1CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 4, 08028 Barcelona, Spain
2Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Dr. Aiguader 88, 08003 Barcelona, Spain
3Universitat Pompeu Fabra (UPF), 08002 Barcelona, Spain
4ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain