The eggNOG database is a database of biological information hosted by the EMBL. It is based on the original idea of COGs (clusters of orthologous groups) and expands that idea to non-supervised orthologous groups constructed from numerous organisms. The database was created in 2007 and updated to version 4.5 in 2015. eggNOG stands for <u>e</u>volutionary <u>g</u>enealogy of <u>g</u>enes: <u>N</u>on-supervised <u>O</u>rthologous <u>G</u>roups.