Fig. 3.

Scatter plots show p-values of presence and number enrichment for all observed 8-mer motifs. P-values are performed under log₁₀ scale. Vertical and horizontal red lines are the thresholds of enrichment, 10e-3. Based on these two lines, each scatter plot can separate in four quadrants. Eight-mer motifs locating in first quadrant are defined as enriched motifs, which are both presence enrichment and number enrichment. The motifs in second quadrants are number enrichment instead of presence enrichment. The 8-mer sequences marked on sequences indicate the top five most-enriched motifs