Lysates were clarified from sonicated nuclei and Fra-1 or Fra-2 complexes were isolated with the appropriate antibodies. ChIP-seq libraries were prepared using the TruSeq ChIP sample reparation kit from Illumina by the MGX sequencing Platform (Montpellier, France) ChIP-seq - Instrument model : Illumina HiSeq 2500 (MGX Platform, Montpellier France)