en gb fr de es it iw el nl da fi sv no pl ru cs



  • Oncogene - A gene that normally encourages cell division. Thus, when an oncogene is activated or deregulated through mutations, it initiates cancerous growth in a cell.
  • Oncologist - A physician who specializes in treating cancer. Some oncologists specialize in a particular type of cancer treatment based on their training in internal medicine, surgery, or radiation therapy, as well as in dermatology, neurology, or other subspecialties.
  • Oncology - The study and treatment of cancer.
  • Open Biopsy - Surgical procedure to remove all or part of a suspicious lymph node for microscopic evaluation.
  • Open-Label Clinical Trial - Clinical trial in which the study participants know the treatment drug they are taking.
  • Opsonization - The process by which antigens are altered so that they are more readily and more efficiently engulfed and destroyed by immune cells.
  • Ozone Holes - Breaks in the protective ozone layer of the atmosphere that significantly increase exposure to ultraviolet radiation. These holes exist over extremely cold areas, particularly over the South Pole and more recently in the Arctic.
  • Ozone Layer - A region in the upper atmosphere that contains a high concentration of ozone, which absorbs many of the ultraviolet rays from the sun.