Does viral DNA cause Disease?

[Learner1]

This was posted today about retroviruses and DNA:

https://www.labroots.com/trending/genetics-and-genomics/15197/viral-dna-human-genome-cause-disease

Retroviruses have genomes that are made of RNA, and when they enter host cells, that RNA is transcribed into DNA. That viral DNA then moves to the host nucleus, and there, it's inserted into the host genome. Millions of years ago, retroviruses interacted with our primordial ancestors and left bits of their DNA behind. That DNA is still carried in our genome; it’s thought that eight percent of the human genome comes from viruses.

The proteins made from potentially reactivated HERV DNA might cause autoimmune problems due to a kind of molecular mimicry.