Cxcl1 enhancer regions illustrating role of transient loss of ATF3 binding. (A) Schematic representation of the genomic region upstream of the Cxcl1 gene, at time points 0h, 0.5h, and 1-2h after stimulation. Two enhancers are shown, one 9kb and one 38kb upstream of the Cxcl1 transcription start site. The H1 enhancer at -38 kb loses ATF3 binding at 0.5h, and gains Rela binding. At the later time points, ATF3 binding is restored, and the enhancer at -9 kb is bound by IRF1, Rela, and STAT1. (B) Average relative probe intensities of the Cxcl1 gene are increased in ATF3 KO compared to WT cells. Average values +/- standard deviation are shown for probe 1457644_s_at (3 replicates), relative to 0h values. Similar plots are shown for two other probes in Supplementary Fig. S5A in Additional file 1.