Reactome is an expert-authored, peer-reviewed knowledge base of human reactions and pathways that functions as a data-mining resource and electronic textbook. Its current release covers approximately 23 per cent of the complete human proteome from UniProt. The pathway browser, search and data-mining tools facilitate searching and visualising pathway data and the analysis of user-supplied high-throughput datasets. A catalogue of all the solute-carrier (SLC) class of transporters which have known ligands has been annotated in Reactome. Reactome provides a detailed and interactive view of this set of transport reactions. Using the example of the SLC class of transporters, we show how they can be overlaid with protein-protein interaction, protein-drug interaction and gene expression data and compared with equivalent pathways in other species, to facilitate over-representation, expression and other pathway analyses.