Endogenous retroviruses (ERVs) are present in the genomes of practically all vertebrates, as a consequence of infiltration of the host germline lineages by circulating exogenous viruses. A typical mammalian genome contains tens to hundreds of thousands of ERV elements, most of which are evolutionarily old and sustained multiple mutation, deletions and rearrangements. Important roles both in physiology and disease processes have been described for some ERV elements, including regulation of host genes, taking part in placenta formation, and influencing immune responses.
Human endogenous retroviruses (HERVs) cover approximately 10% of the human genome sequence. Various groups of HERVs have been described, ranging in numbers from one to many thousand copies. The pattern of HERV expression has been linked to various diseases, including multiple sclerosis, amyotrophic lateral sclerosis, rheumatoid arthritis and various cancers. Because of the high complexity of HERVs and difficulty in their classification and nomenclature, it is important to provide the scientific community with a database resource of these genetic elements.
This database is compiled from the human genome nucleotide sequences obtained mostly in the Human Genome Projects. We created a relatively simple and fast environment for screening human genome for HERVs. This makes it possible to continuously improve classification and characterization of retroviral families.
This is the first publicly available HERV database, that allows users to access individual reconstructed HERV elements, including their sequence, structure and other features. Running from 2002, we were cited more than 70x. 
You can search by HERV families, chromosome positions and several other features. Results are linked to other bioinformatics databases, namely genome browsers ENSEMBL and UCSC. Metodology of transposone reconstruction can be used on other genomes as well.