Table 1.

Significant gene numbers at different cutoff levels

	FDR 0.5%	FDR 0%	FDR 0% minimum 2 fold
Sufficient N vs. mild N	157	120	52 (51a, 1b)
Sufficient N vs. severe N	2176	461	461 (271a, 190b)
Severe N vs. 2 hr induction	146	90	90 (77a, 13b)
Severe N vs. 24 hr induction	2523	905	837 (481a, 356b)

Significance analysis of microarray (SAM; academic version 2.23B) was used to identify differentially expressed genes. Different number of significant genes could be obtained depending on the SAM median false discovery rate (FDR) and a minimum fold change. ^a number of genes up-regulated; ^b number of genes down-regulated