Identifying the range of motif enrichment. Each plot tracks the number of occurrences of a given motif in enriched promoter sequences within a sliding window. The lower dotted line indicates the number of occurrences expected by chance. The range in position was determined by taking the approximate point at which the largest peak crosses the 99th percentile (upper dashed line) calculated using a Poisson distribution. For each motif, this range is marked by the colored lines above and below each plot.