PathIN is a web-service that provides an easy and flexible way for rapidly creating pathway based networks, at several functional biological levels: genes, compounds and reactions. The proposed tool holds a large database repository of reference pathway networks, across a large set of species, which have been developed through the freely available information included in the KEGG, Reactome, and Wiki Pathways database repositories.

PathIN provides networks by means of five diverse methodologies: (a) direct connections between pathways of interest, (b) direct connections as well as the first neighbours of the given pathways, (c) direct connections, the first neighbours and the connections in between them, and (d) two additional methodologies for creating complementary pathway-to-pathway networks that involve additional (missing) pathways that interfere in-between pathways of interest.

The underlying tool is expected to be used as a simple yet informative reference tool for understanding networks of molecular mechanisms related to specific diseases.

PathIN requires four general steps to search for specific pathways of interest and create their network.