If you are experiencing pain on top of your foot, you should consider seeing your doctor as soon as possible. Pain in this location is not normal, and usually indicates a more serious problem. Catching conditions and injuries such as stress fractures in their early stages is vital to successful treatment.
Natural killer cell: A cell that can react against and destroy another cell without prior sensitization to it. Abbreviated NK cell. NK cells are part of our first line of defense against cancer cells and virus-infected cells. NK cells are small lymphocytes that originate in the bone marrow and develop without the influence of the thymus. An NK cell attaches to a target cell, releases chemicals that breach its cell wall, and causes it to lyse (break up).
Cancer cells are cells that grow and divide at an unregulated, quick pace. Although cancer cells can be quite common in a person they are only malignant when the other cells (particularly natural killer cells) fail to recognize and/or destroy them. In the past a common belief was that cancer cells failed to be recognized and destroyed because of a weakness in the immune system.