a, b, Box plot visualization of cell-type differences in burst frequency and size, as a function of fold changes in mean expression between cell types, as in Fig. 3c. c, d, Box plots of the fold change in mean expression for the top 100 genes in each direction for burst frequency and size, respectively (n = 100 genes in each group, two-sided t-test). e, f, Box plots of the fold change in normalized read density of H3K27ac in enhancers (enhancer magnitude) between cell types. Enhancer linked to genes that had top 100 changes in either burst frequency or size (n = 100 genes in each group, two-sided t-test). g, Rolling median (n = 50) of SNPs per enhancer ordered by the P value of burst size difference between the CAST and C57 allele in fibroblast cells (profile likelihood test, no adjustment for multiple comparisons).