In people who have been taking ART for several years and who have no other co-infections, HIV-infected cells produce very few copies of HIV and appear to infect other cells at a relatively low rate. In many of these cases, HIV can lie dormant (latent) in cells that are resting, until stimulated from time to time. As part of an attempt at curing HIV, it would be important to rid the body of these infected cells. Driving HIV out of hiding in these cells is sometimes called "purging latently infected cells" by researchers.
Several years ago Canadian researchers attempted to cure HIV by giving ART users the anti-seizure drug valproic acid in addition to ART. However, this did not work.