1. Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG) The Barcelona Institute of Science and Technology Dr. Aiguader 88, Barcelona 08003 Spain
2. Department of Experimental Sciences, Universitat Pompeu Fabra (UPF) Dr. Aiguader 88, 08003 Barcelona Spain
3. ICREA Pg. Lluís Companys 23, 08010 Barcelona Spain