The human papilloma virus causes most — but not all — cases of cancer of the cervix. James Cavallini/ScienceSource hide caption

itoggle caption James Cavallini/ScienceSource

Two cervical cancer cells divide in this image from a scanning electron microscope. Steve Gschmeissner/Getty Images/Science Photo Libra hide caption

itoggle caption Steve Gschmeissner/Getty Images/Science Photo Libra