The STRING database in 2011: functional interaction networks of proteins, globally integrated and scored.
Szklarczyk D, Franceschini A, Kuhn M, Simonovic M, Roth A, Minguez P, Doerks T, Stark M, Muller J, Bork P, et al. Nucleic Acids Res. 2011 Jan; 39(Database issue):D561-8. Epub 2010 Nov 2.