Table 1.

Four types of IntPath unified gene relationships.

Unified Genes Relationships	Explanation
ECrel	Enzyme-enzyme relation, indicating two enzymes catalyzing successive reaction steps.
PPrel	Protein-protein interaction, such as binding and modification, or proteins have control over the same process.
GErel	Gene expression interaction, indicating relation of transcription factor and target gene product.
GPrel	Proteins belong to the same molecular complex, not necessarily interacting directly.

Explanations of the types of relationships in IntPath are given below.