About 8% of the human genome consists of endogenous retroviruses. Retroviruses – like HIV – carry the ability to reverse transcribe themselves from RNA into DNA, integrating into the host genome. The discovery of EBLN2 in 2010 was surprising, though, because it came from Borna virus, which is not a retrovirus. Borna is an RNA virus that infects the brain and is deadly in sheep and horses (it was named after a German town where an outbreak in horses occurred), but infects humans with no clear effects besides possible correlations with psychiatric disease.
Click here to see the sequence of Day 67 with EBLN2 underlined.