A very common type of genetic engineering involves inserting DNA from one organism into another. An example is the insertion of a human gene into a circular DNA plasmid from a bacterium. Then that engineered plasmid is taken in by another bacterium and the product of the human gene is generated in large quantities.
One of the first human products from this process was insulin - pure human insulin.
Another use is to genetically engineer resistance to the herbicide glyphosate (Roundup) in a crop, so that the herbicide won't kill the crop.
Human growth hormone is used to treat growth disorders in children and has some uses in adults.
Golden rice, which is produced by moving genes for Vitamin A from daffodils into rice helps prevent blindness in countries where nutrition is poor.
Glowing organisms are produced by inserting a jellyfish gene into another species. This gene has been useful as a marker to show whether other genes have been taken in by an organism.
Spider silk is tremendously strong and is produced often by taking a gene from a weaving spider and inserting it into a goat egg; the milk will have the strong silk.
Bovine Growth Hormone is used to increase milk production in cows.
Bt crops are crops that have a gene from a bacterium inserted; this gene product makes the crop resistant to certain insects.
bovine growth hormone