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).
B cells are a specific type of white blood cell called a lymphocyte. Other types of lymphocytes include T cells and natural killer cells. B cells develop from stem cells in bone marrow. They remain in the bone marrow until they become mature. Once they are fully developed, B cells are released into the blood where they travel to lymphatic organs. Mature B cells are capable of becoming activated and producing antibodies.