A) Functional assay testing of cEnh regulatory activity in C2C12 cells. 
Fold activity in myocytes across technical replicates (n = 4) is shown. TF occupied cEnhs and occupancy negative controls were each sorted by their mean fold activity. The red arrow corresponds to the mean fold activity threshold above which elements are considered active. In addition, DNAse hypersensitivity, H3K27ac status, and myogenin occupancy are shown for each cRE, both as RPM scores (highest signal in dark blue to low signal in yellow), and as binary (IDR=0.05) calls (red coloring indicates occupancy). The number of motifs (purple heat map) present within the cEnh region are shown for both the classical muscle E-Box (CAGSTG) and the myogenin occupancy derived expanded motif (RRCAGSTG).

B) Functional assay testing of cEnh regulatory activity in Erythroid cells. 
Functional assay testing of the regulatory activity of erythroid cEnhancers. Fold activity in K562 cells across biological replicates (n 2 [1; 9]) and technical replicates (n = 4 for each biological replicate) is shown. The cEnhs and occupancy negative controls were sorted by their mean fold activity. The red arrow corresponds to the mean fold activity threshold above which elements are considered active (p=0.05). In addition, DNAse hypersensitivity, H3K27ac status, GATA1/Tal1 occupancy are shown for each cRE, both as binary (IDR=0.05) calls (red coloring indicates occupancy), and as RPM scores (heatmap with blue indicating high signal). The number of motifs (purple heat map) present within each cEnh are shown for both the TAL1 (CAGMTG) and GATA1 (WGATAA) motifs.