Briefly, ~6x10e7 cells were fixed in 1% formaldehyde for 11 minutes, quenched with glycine, lysed, and then sonicated to generate final DNA fragments of 150–600 bp. The soluble chromatin was diluted 1:10 and pre-cleared with protein A:G beads for 2 hours. Remaining chromatin was incubated with primary antibody overnight, then protein A:G beads were added for an additional 2 hours. Beads were washed and then de-crosslinked overnight. ChIP-seq libraries were prepared from IP samples using an Ovation Ultralow Library System kit (NuGEN Technologies., San Carlos, CA, USA). ChIP-seq libraries were pooled (12-plex) and clustered onto two flow cell lanes.