Using tissue-specific PPI networks can potentially reduce false positive PPI (well-known in general PPI network) and improve the accuracy of the current network for your given tissue.
The tissue-specific PPI data is from DifferentialNet, which was produced by integrating experimental binary PPI data with RNA-sequencing profiles from different tissues, collected by the Genotype-Tissue Expression (GTEx) consortium. Each PPI was given a score for each tissue that indicates whether the corresponding genes were similarly expressed across many tissues, or significantly dys-regulated only in the tissue of interest.