zur Hausen’s discovery paved the way for vaccines against human papillomavirus, or HPV, a sexually transmitted disease that can also cause other cancers, including of the vagina, vulva, penis, anus and back of the throat. “I felt some satisfaction in this situation, because up to this moment several colleagues had ridiculed our research, saying, ‘Everyone knows that warts and papillomaviruses are harmless,’” Dr. Friends and colleagues said they knew almost nothing about that marriage, noting that Dr