Programming MAbs  MAbs can be programmed to serve purposes other than reacting against specific cancer cells .
• MAbs can be programmed to be specific against cell growth factors, for example. This will interfere with the
  growth of cancer cells, which are frequently dependent on such factors.
• MAbs can be very helpful in some cases of bone marrow transplantation. Often, a cancer patient will donate
  his or her own marrow before heavy radiotherapy or chemotherapy , with the idea that it will be returned after
  treatment. But one problem with this kind of procedure (called an autologous transplant) is that cancer cells
  might be in the bone marrow. If the marrow is removed, stored and reintroduced, the cancer cells would be put
  right back and the cancer would recur. MAbs can be effective in purging the bone marrow cells of any cancer
  cells if the marrow is treated while it is outside the body.
• MAbs against a specific cancer cell can also be programmed to carry a radioisotope source to the tumor . This
  "radioactive-labeled" antibody will find the cancer cell and attach to it; the radioactive particles then destroy
  the tumor cells.
      One problem is that the therapy requires an isotope strong enough to kill cells in the area of the target cancer
  cell. With radioactive iodine (I-131)-labeled antibodies, this treatment has been used successfully in cases of
  lymphomas, which are very radiosensitive tumors. But it is hard to deliver enough radiation to kill cells when