Table 3. Statistical significance of the differences in GC content between the 30 nt low conservation window and the rest of 3′-UTRs^a.

	A
	t	P
Human UGA	11.823	7.63E–16
Human UAG	9.471	2.19E–12
Human UAA	7.128	1.71E–09
Yeast UGA	4.278	5.01E–05
Yeast UAG	0.674	0.251452
Yeast UAA	4.299	4.53E–05

^aThe comparison was between positions 1–30 and 31–100 of the UTRs.