The three largest International DNA databases are the European Bioinformatics Institute's (EBI) EMBL, the US National Center for Biotechnology Information's (NCBI) GenBank, and the DNA Data Bank of Japan. They rank at the top of the list for traffic, followed by the EBI's Swiss Prot, a protein sequence database, and EnsEMBL, EBI's annotated metazoan genome browser. Filling out the toolbox are the model organism databases (MODs), including WormBase and FlyBase, and Gramene, a resource for rice and grass genomics. All these databases contain extensive sequence information and genome maps. Some allow searches for sequences and for gene products and expression patterns. BLAST, NCBI's search engine that compares recent findings with known information, can be used to detect similarities between nucleotide sequences or protein sequences.