OncoMouse TM was one of the first mammals to be patented. The OncoMouse TM is genetically engineered to be susceptible to cancers. In 1984 Harvard University and DuPont jointly received a US patent on the biotech process used to create the mouse, on the mouse itself, and on all other mammals genetically altered by the technology.

They couldn't get a patent in Canada, though. Judge Marc Nadon, of the Federal Court of Canada, ruled: "They have created a method to inject eggs with a myc gene but they have not invented the mouse."