Provides a set of tools for searching and browsing the Gene Ontology (GO) database. AMIGO visualizes speciation, duplication and horizontal gene transfer events, sequence alignments and descriptive data and external links for both proteins and annotations. The workflow annotation is a two-step process: (i) curators create a model of evolution that is consistent with the observed experimental annotations of modern-day sequences. Once constructed, this model is used in a (ii) step to create inferred annotations over the entire tree. This search box was designed to involve strict selection of terms, which results in coherent annotations within proteins families, as well as across families implicated in a single process.