 As of September 2014, the network presented in iHOP contains 28.4 million sentences and 110,000 genes from over 2,700 organisms, including the model organisms "Homo sapiens", "Mus musculus", "Drosophila melanogaster", "Caenorhabditis elegans", "Danio rerio", "Arabidopsis thaliana", "Saccharomyces cerevisiae" and "Escherichia coli".The iHOP system has shown that by navigating from gene to gene, distant medical and biological concepts may be connected by only a small number of genes; the shortest path between two genes has been shown to involve on average four intermediary genes.The iHOP system architecture consists of two separate parts