Table 2.

Simulated down-regulation for 300 random genes^a

	4-fold	2-fold
Oligo(dT)	166 (55%)	130 (43%)
pm19	191 (64%)	49 (16%)
pm22	119 (40%)	92 (31%)
pm28	71 (24%)	27 (9%)
Combined	256 (85%)	165 (55%)

^aSignal intensities for 300 randomly chosen genes from refed fibroblasts were divided by 2 and 4. These channel intensity values were then replaced with the channel intensities from the probe with a mean nearest these divided means, thereby mimicking 2- and 4-fold down-regulation, and including the appropriate variance. This table contains the number of genes that were scored as differentially regulated by limma with P ≤ 0.05 (% of 300 is indicated in parentheses).