Finding out the regulating transcription factors of a list of genes ? - (Jun/21/2014 )

Hi, I've got a list of 25 genes and need to find out if they're regulated by common transcription factors.

What's the best way / online tool to find this out?

I'd be grateful for any ideas !

Tabaluga

OK, just managed to find two websites:

http://gather.genome.duke.edu/

http://trap.molgen.mpg.de/cgi-bin/pastaa.cgi

Still, if anyone knows a more reliable way or has a comment, I'm interested...