Table 2.

Summary of the number of differentially expressed genes between the studied groups.

Comparison		P < 0.01 adjusted for multiple comparison P < 0.01	P < 0.01; fold change >1.5
5th DOL	Genes presented a positive monotone trend (expression in extremely preterm is lower than that in very preterm; expression in very preterm is lower than that in moderately preterm)	56
	Genes presented a negative monotone trend	82
28th DOL	Genes presented a positive monotone trend	253
	Genes presented a negative monotone trend	55
5th DOL versus 28th DOL (paired t-test)	Genes whose expressions were significantly higher on the 28th DOL compared to those on the 5th DOL	1522	150
	Genes whose expressions were significantly lower on the 28th DOL compared to those on the 5th DOL	2909	337
Extremely preterm infants measurement on the 28th DOL versus very preterm infants measurements on the 5th DOL	Genes whose expressions were significantly higher in the group of extremely preterm infants compared to those in the group of very preterm infants	176	29
	Genes whose expressions were significantly lower in the group of extremely preterm infants compared to those in the group of very preterm infants	186	27