The top 5 enriched motifs in loci exhibiting increased accessibility (Fos, BATF, FRA1, Atf3, and AP-1) are all subunits or dimers of the AP-1 protein family.34 AP-1 activity is regulated by physiological and pathological stimuli like cytokines, stress signals, infections, and oncogenic stimuli. Here, ATF3 is linked to infection.