The continuous growth in culture of mouse myeloma cells fused to immunized spleen cells was first described by Kohler and Milstein in 1975 (1). The fused hybridoma cells secrete monoclonal antibodies of predefined specificity that arc widely used in biological research and in newly developed clinical applications such as diagnosis and treatment of cancers, hematopoietic tumors, and rejection in bone marrow and kidney transplantation. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.