Abstract: Transitive assignment of GO terms based on the UniPathway pathway vocabulary. UniPathway is a manually curated resource of enzyme-catalyzed and spontaneous chemical reactions. It provides a hierarchical representation of metabolic pathways. Descriptions of the pathway(s) that a particular protein is involved in are included in UniProtKB records. UniPathway data are cross-linked to existing pathway resources such as KEGG and MetaCyc. Further information on the UniPathway resource is available at http://www.unipathway.org/obiwarehouse/unipathway. When a UniPathway pathway describes a concept that is within the scope of the Gene Ontology, it is investigated to determine whether it is appropriate to map the term to an equivalent term in GO. The mapping between UniPathway terms and GO terms is carried out manually. Definitions and hierarchies of the terms in the two resources are compared and the mapping generated will reflect the most correct correspondence. The translation table between GO terms and UniPathway pathways is maintained by the UniPathway team and is available at http://www.grenoble.prabi.fr/dev/obiwarehouse/download/unipathway/public/unipathway2go.tsv.