[BioC] Overlapping genes in subsets of lists

[Heike Pospisil]

Hello there,

I have 100 lists of differentially expressed genes, and I am trying to find 
genes overrepresented in these 100 lists (I call them a 'cluster of genes').
What's worse, I expect not only one cluster of genes, but three or four or 
five of them. That is why, a simple intersection() will not help. I wish to 
had a function that can select all genes which appear in 100% of 33 lists of 
genes (cluster 1), all genes which appear in 100% of 22 lists (cluster 2) and 
all genes which appear in 100% of the remaining 45 lists (cluster 3). (I hope 
my explanation is clear).

Does anybody know a package or a strategy how to define such clusters?

Thanks and best,
Heike
-- 
Dr. Heike Pospisil      | pospisil at zbh.uni-hamburg.de
University of Hamburg   | Center for Bioinformatics 
Bundesstrasse 43        | 20146 Hamburg, Germany 
phone:+49-40-42838-7303 | fax: +49-40-42838-7312