Arina A, Murillo O, Dubrot J, Azpilikueta A, Alfaro C, Pérez-Gracia JL, Bendandi M, Palencia B, Hervás-Stubbs S, Melero I. Cellular liaisons of natural killer lymphocytes in immunology and immunotherapy of cancer. Expert Opin Biol Ther. 2007 May; 7(5):599-615.