Accessibility of Sp1 motif-containing differentially accessible regions (DARs) and expression of associated genes according to 1,3-butadiene (BD) exposure and strain. (A) Differences in chromatin accessibility in proximal regions containing the Sp1 motif in the lung of control and 1,3-butadiene-exposed mice of both strains (independent t-test, *, **) (B) Differences in messenger RNA (mRNA) level of genes associated with these regions in the same tissues (independent t-test, *, **). (C) Difference in mRNA level of the immune response pathway gene Irf7, the locus for which contains an Sp1 motif, following 1,3-butadiene exposure in C57BL/6J and CAST/EiJ mice.