As we know that many problem in bioinformatics can be formulate into weighted graph matching problem.
For example in this paper the author mentioned that alignment of the PPI network is actually a weighted graph matching problem, which the weight of edges are the experimental evidence of the pair of proteins.
Yet in most of the database like BioGrid and Uniport I cant find any values like "confidence score" of specific interaction.
I would like to ask:
i) Where can I find such "confidence score" of interaction?
ii) Is there any biological network other than PPI network involve weighted graph matching?