[ILLUSTRATION OMITTED]

[4] STOCKHOLM, Sweden -- By 1983, AIDS was becoming a deadly epidemic. No one knew what was causing it, and there was no treatment. Then, French scientists Luc Montagnier and Francoise Barre-Sinoussi discovered an unusual virus in the blood of an AIDS patient. The

That discovery helped scientists find ways to fight acquired immune deficiency syndrome, a disorder that has killed more than 25 million people worldwide. For their work, Montagnier and Barre-Sinoussi won half of this year's $1.4 million Nobel Prize in medicine. The other half of the prize went to German scientist Harald zur Hausen, who found that another virus, human papillomavirus, or HPV, causes cervical cancer in women. Learn about other Nobel laureates at tinyurl.com/nobel6.