History

Abstract

The history of the H-2 system (see Appendix) begins with the advent of tumor transplantation at the turn of the century. By that time, tumor biologists had realized that cancer was a complex disease, with each tumor displaying a certain individuality and uniqueness. Because this individuality limited the length of time a particular tumor would be available, experimenters sought to prolong the observation period by transplanting the neoplastic tissue from one animal to another. However, most attempts at tumor transplantation gave unsatisfactory results because even the few tumors that actually grew in the new host survived only a short time. Only occasionally was a prolonged survival observed, but the conditions under which this occurred were not known. The turning point in the investigation came through the use of inbred stocks of mice by Carl O. Jensen at the Agriculture and Veterinary Institute in Copenhagen, Denmark, and Leo Loeb at the University of Pennsylvania in Philadelphia, Pennsylvania.