Dr. Harald zur Hausen, a celebrated German virologist who was awarded the Nobel Prize in Medicine in 2008, died at the age of 87. He had worked tirelessly to discover that human papillomavirus (HPV), the virus responsible for warts, was actually the cause of cervical cancer, a ground-breaking discovery that led to the development of vaccines and life-saving tests for HPV. In addition, HPV is responsible for other types of cancer as well, including cancers of the vulva, penis, throat, anus, and vagina. More than 600,000 people worldwide develop HPV-related cancers annually, and vaccines can prevent as many as 90 percent of these cancers. Dr. zur Hausen was highly respected by his colleagues and was described as courteous, respectful, and a “gentleman.” He was also deeply devoted to his research and refused to be deterred when he felt he had a valid hypothesis to pursue. Despite criticism and skepticism from many in the scientific world, Dr. zur Hausen dedicated a decade to prove that HPV was responsible for cervical cancer. His hypothesis contradicted the prevailing belief that herpes simplex virus caused the cancer. He eventually succeeded in his quest and identified two HPV types responsible for the cancer. Dr. zur Hausen contributed significantly to scientific understanding of HPV through his willingness to share with other researchers and offer new direction in studying the virus. He championed the development of the HPV vaccine, which was originally introduced for girls, but which health officials now recommend should be given to both boys and girls. An intensely private person, Dr. zur Hausen is survived by his wife, Ethel-Michele de Villiers, and three sons. Among the cancers he later studied were breast, colon, and other types.