STRING is a database of predicted protein-protein interactions at EMBL. It cluster the results from many sources of protein-protein interactions databases, like Mint, etc.., and it also use the informations from KEGG-pathways and reactome, to provide the best annotations for the interactions of a protein.
I am a bit confused from the results that I see there, because when I look at the genes in the pathway I am studying, I see many errors and annotations that I don't understand.
What is your experience with STRING? If you want to do me a favor, go there and try to see the interactions annotated for a gene that you know already. Do you see anything weird?