filtering differentially expressed genes with Bioconductor??

Hi,

I am relatively new to R and Bioconductor and am trying to filter the topTable that I generated of differentially expressed genes from my normlized eset file comprised of ~ 40 HG-133A Affy microarrays . I would like to see if particular probesets are represented in this list. Alternatively I would like to
generate a topTable of differentially expressed genes using only specified probesets within my eset
file.

Can anyone tell me how I would begin to approach this? I have looked into using the genefilter() function but can’t figure out if it can take the right parameters (i.e. specific probe set id’s).

Thanks in advance,
-M

This is the code I used to generate my topTable

> fit <- lmFit(eset, design) > cont.matrix <- makeContrasts(NormalvsTumor=Tumor-Normal, levels=design) > fit2 <- contrasts.fit(fit, cont.matrix) > fit2 <- eBayes(fit2) > topTable(fit2, number=100, adjust=”BH”)