Not everyone who is infected with HIV goes on to develop AIDS. A tiny fraction of HIV-positive adults holds the line against AIDS by mounting a very strong immune response; but, research has found that such an approach often contributes to the development of other illnesses, such as heart disease and cancers. Scientists at Oxford University looked at so-called pediatric non-progressors, the 5 to 10 percent of children infected with HIV who don't develop AIDS, even without treatment. Their study of 170 HIV-positive South African children revealed that their immune systems were behaving differently than adults'. Like non-human primates that harbor the simian version of HIV without becoming sick, there was very low immune activation even with high levels of the virus in their blood. Lead researcher Philip Goulder said, "(The) lack of HIV disease here seems to result from avoiding making strong immune responses against HIV." Experts said the findings, published in Science Translational Medicine, could be the first signs of people co-evolving with HIV and eventually lead to new therapies for all patients infected with the AIDS virus.