Endogenous retroviruses (ERVs) are genetic elements that were integrated into the host genome more than 100 million years ago. Their integration took place in germ cells, ensuring their vertical transmission in the human population. They are currently thought to make up to 8 % of the human genome. During evolution, various mutations have accumulated in endogenous retroviruses, leading to their dysfunction, and were therefore considered as junk DNA in the past. However, in recent years it has turned out that they are not completely dysfunctional. With more data becoming available from human genome analyses, their potential roles in the human body are being revealed.
Keywords: endogenous retroviruses; genome; integration.