Dr. George Papanicolaou discovered that it was possible to detect cancer by inspecting cervical cells. The Pap smear, the cervical cancer screening test, is named after him.
American Cancer Society/AP
Dr. Donald Brown inoculated Kelly Kent with the HPV vaccine in his Chicago office in the summer of 2006 — not long after the first version of the vaccine reached the market.
Charles Rex Arbogast/AP