The distributions of functional semantic similarity scores derived from coexpression chromosome domains in ESC and EB, and from a randomized gene set. The green line on the plot represents the distribution from the random data, the blue and red lines are those from ESC and EB, respectively. The X-axis indicates functional semantic similarity scores, and the Y-axis indicates the accumulative probability of coexpressed genes in domains. For the random gene set, the cumulative probability reached to 1 when the functional similarity was up to 8. That means all the random gene pairs have the functional similarity 8 or below. For coexpression domain genes of ESC and EB, the cumulated probability did not reaches 1 (i.e. 100% of gene pairs) until the functional similarity was over 35, indicating higher functional similarities from more coexpressed genes. The distributions from ESC and EB domain gene sets were similar to each other but significantly different from that from the random gene set (p < 10E-10 by the Kolmogorov-Smirnov test).