Provides a database on protein phosphatases. PhosphaBase contains more than 2800 phosphatase entries from over 340 species ranged from the genomic level to 3D protein structures. The gene ontology consists of three parts: molecular function, biological process and cellular component. The search engine can use a series of preformed or canned queries. The architecture and organization of this repository can be utilized as basis for developing similar bases for other enzyme families.