Abstract
A review was made of past contributions of the experimental study of metastases and of current methods of animal tumor investigations used in the laboratory of the Surgery Branch of the National Cancer Institute. Certain associations between the growthand metastasizability of malignant tumors in laboratory animals and of malignant disease in humans were noted. There were many clinical concepts which were duplicated in the laboratory animal which showed the bizarre behavior of cancer. It was apparent that malignant disease, in humans or laboratory animals, must be individualized.