Table 1. Length parameter of each gene class.

	Genomic Sequence	CDS	5′ UTR	3′ UTR	Total Exon	Total Intron	# of Exon	# of Intron
SP	16,835 a	1,097	139	599	2,158	14,370	6 b	5
AP	41,017	1,638	183	1,062	3,274	37,314	11	10
Pvalue c	<2.2e-16*	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16
AP = 2	28,100	1,415	172	881	2,808	25,162	9	8
Pvalue d	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16
AP = 3∼4	48,058	1,763	188	1,178	3,492	43,650	12	11
Pvalue e	<2.2e-16	<2.2e-16	2.153e-05	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16
AP> = 5	90,787	2,296	207	1,325	4,178	87,204	17	16
Pvalue f	<2.2e-16	<2.2e-16	0.000329	0.0005684	<2.2e-16	<2.2e-16	<2.2e-16	<2.2e-16

The table showed that genes with more alternative promoters tend to have increased length in all aspects of gene structure parameter. SP means gene with single promoter while AP means gene with alternative promoters. AP = 2, AP = 3∼4, and AP> = 5 means gene with only 2 promoters, 3 or 4 promoters, and at least 5 promoters, respectively.

^a: Median length;

^b: Median count;

^c: Wilcoxon rank sum test, AP vs. SP.

^d: Wilcoxon rank sum test, AP = 2 vs. SP.

^e: Wilcoxon rank sum test, AP = 3∼4 vs. AP = 2.

^f: Wilcoxon rank sum test, AP> = 5 vs. AP = 3∼4.

^*: The Wilcoxon rank sum test function in R (wilcox.test) returns “P<2.2e-16” when P is smaller than 2.2e-16.