Dr Marc-André Langlois discusses his research into the immune response to retroviruses, as well as his new technique for screening DNA for rare mutated proviral sequences

Retroviruses are everywhere; all vertebrate animals (cats, dogs, birds, fish, primates and humans) have them encoded in their DNA. In fact, about 8 per cent of the human genome is composed of retroviruses. Most of these endogenous animal retroviruses are inactive through mutations and sequence deletions, however some can go on to infect new cells, new hosts and even different animal species. In addition to often being directly harmful to the cells they infect, some retroviruses are also known to cause cancer.