A biotechnological process used to produce many useful and valuable products with medical, healthcare, agricultural, and veterinary applications. It involves taking genes from the cells of a living organism and transferring them to the cells of another organism. The genes transferred contain the genetic code for the expression of a required biochemical product, such as a protein with therapeutic properties, or provide resistance to an antibiotic or other substance. Recombinant human insulin, used for the treatment of diabetes, has virtually replaced insulin derived from pigs and cows, and is produced by bacteria containing human genes. Human growth hormones, hepatitis B vaccine, blood-clotting agents known as Factor VIII, anti-cancer drugs, and vaccines against scours, a toxic diarrhoea in pigs, are all produced by recombinant DNA technology. Crops developed through recombinant DNA technology that are resistance to herbicides, insects, low moisture, and other environmental conditions include rice, maize, canola (oil-seed rape), and cotton. The biotechnology was pioneered by Stanley Cohen from Stanford School of Medicine and Herbert Boyer from the California School of Medicine, San Francisco in 1973.