The natural killer cell

In view of the rapidly accumulating data, it seems certain that immunologists and clinicians alike must continue to consider and work with a new class of lymphocytes referred to as the NK cells. This is especially true for those concerned with resistance to cancer, bone marrow transplantation and infection. Although the role played by this cell in the body economy is still uncertain, it now seems established that NK cells can effect rejection of transplantable tumor cell lines in vivo. A wide range of speculations concerning the biologic importance of the NK cell system(s) remains to be elucidated.