Figure 4From: Two different classes of co-occurring motif pairs found by a novel visualization method in human promoter regionsDistributions of the number of unique EST libraries for the genes related to each class. The X-axis represents the number of different EST libraries in which the expression of a gene is observed, which is regarded to be a measure of ubiquitous expression. The Y-axis represents the frequency of genes corresponding to the bin of the X-value.Back to article page