Table 1.

Alternative 5′ss selection and resulting exon length correlation. The table reports how frequently the major isoform contains the stronger splice site when the alternative splice site lies within one of three different exon size classes. ^a,bWithin a column, means without a common superscript differ (p < 0.05) between size categories in each column. ¹29% preference for the upstream 5′ss. ²42% preference for the upstream 5′ss. ³44% preference for the upstream 5′ss.

	Exon size generated with major splice site usage
Exon size generated with minor splice site usage		Ex ≤50 nts	50< Ex ≤250 nts	Ex >250 nts
	Ex ≤50 nts	98%a1	86%a	100%a
	50< Ex ≤250 nts	73%b	87%a2	88%a
	Ex >250 nts	75%b	58%b	77%b3