Luc Montagnier was a French virologist best known for his discovery of the HIV virus, which causes AIDS. His groundbreaking research in the early 1980s helped to identify the virus and contributed significantly to the understanding of how it affects the immune system. For this work, he was awarded the Nobel Prize in Physiology or Medicine in 2008, sharing the honor with Françoise Barré-Sinoussi. In addition to his work on HIV, Montagnier explored other areas of virology and immunology. Later in his career, he became involved in controversial research related to water memory and homeopathy, which sparked debate within the scientific community. Despite the controversies, his contributions to virology remain significant.