A centralized gene-annotation portal that enables researchers to access distributed gene annotation resources. The unique features of BioGPS, compared to those of other gene portals, are its community extensibility and user customizability. Users contribute the gene-specific resources accessible from BioGPS (‘plugins’), which helps ensure that the resource collection is always up-to-date and that it will continue expanding over time. BioGPS users can create their own collections of relevant plugins and save them as customized gene-report pages or ‘layouts’. In addition, we recently updated the most popular plugin, the ‘Gene expression/activity chart’, to include ∼6000 datasets (from ∼2000 datasets) and we enhanced user interactivity.