• open in new windowHomoloGene - a system for automated detection of homologs at NCBI
• open in new windowDOOP - Database of Orthologous Promoters
• open in new windowInparanoid - Eukaryotic Ortholog Groups
• open in new windowHOVERGEN - Homologous Vertebrate Genes Database
• OrthoMCL - Ortholog Grouping for Protein Sequences from Multiple Genomes
• open in new windowOrthologID - identifies orthologous groups for complete genomes
• open in new windowHCOP - HGNC Comparison of Orthology Predictions
• open in new windowYOGY - resource for retrieving orthologous proteins from ten eukaryotic organisms
• open in new windowOrthoDisease - a database of Human Disease Orthologs