 Endogenous retrovirus

A retroviral sequence inherited as part of the host genome. Some families retain mobilization capacity, whereas others are inactive remnants.

Endogenous retroviruses (ERVs) are sequences of viral DNA that have integrated into the genomes of a host organism, typically a vertebrate, and have been passed down through generations. They are remnants of ancient viral infections where a retrovirus successfully invaded the germline cells (the reproductive cells) of a host, allowing the viral genetic material to be incorporated into the host's DNA.