11.   Recombinant DNA techniques made it possible to splice the gene for human insulin into bacteria.

12.   That calmed fears of the technology, which went on to create a way to discover and develop protein-based drugs like human insulin and erythropoietin.

13.   The fragments were many copies of the human insulin gene.

14.   They also amended their agreement that allows Lilly to make and sell genetically engineered human insulin.

15.   Under a contract signed that year, it agreed to pay the City of Hope to synthesize the gene for human insulin.

16.   When the bacteria grew, they produced human insulin, becoming factories to make a drug safe for human use.

17.   Pigs were chosen because diabetics for years used porcine insulin, which has just one amino acid different from human insulin.

18.   Such a process could be used in breeding cows that produce more milk, or chickens or pigs that produce human insulin.

19.   The insulin produced in the Soviet Union was made from animal hormones, whereas Western companies produce genetically engineered human insulin.

20.   Then, in some of the rats, they delivered copies of the human insulin gene to other cells of the pancreas.