Lysates were precleared with Protein G Dynabeads. Complexes were then isolated with 10µg anti-GFP monoclonal antibody (Invitrogen A11120, clone 3E6, IgG2a), polyclonal rabbit anti-Irf1 antibody (M-20, Santa Cruz, SC-640) or control rabbit IgG (Santa Cruz sc-2027, Mouse IgG) linked to Protein G Dynabeads. Sequencing libraries were then prepared using the Illumina ChIP-seq DNA Sample Prep Kit. Libraries were size selected at ~200bp and four libraries were multiplexed per lane on a HiSeq 2000.