Researchers have discovered how Human Immunodeficiency Virus, which causes AIDS, can hide itself in our cells and dodge the attention of our normal defenses. When a normal virus such as the common cold infects people we develop an immune response and produce defense cells which can quickly get rid of the virus. But when HIV infects us it can last for our whole life. HIV does this by successfully hiding from our immune cells, which are seeking to identify and destroy the virus, fooling them into thinking that it is part of the normal trash in a cell rather than being clearly visible on the cell surface.