Although human gene therapy is still relatively new, it has been used to treat genetic disorders such as severe combined immunodeficiency, and Leber's congenital amaurosis.
Genetically modified crops are publicly the most controversial GMOs.
The majority are engineered for herbicide tolerance or insect resistance.
Countries have adopted regulatory measures to deal with these concerns.
There are differences in the regulation for the release of GMOs between countries, with some of the most marked differences occurring between the US and Europe.
A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques.
The exact definition of a genetically modified organism and what constitutes genetic engineering varies, with the most common being an organism altered in a way that "does not occur naturally by mating and/or natural recombination".
The first genetically modified animal to be commercialized was the Glo Fish (2003) and the first genetically modified animal to be approved for food use was the Aqu Advantage salmon in 2015.
Bacteria are the easiest organisms to engineer and have been used for research, food production, industrial protein purification (including drugs), agriculture, and art.
One of the key issues concerning regulators is whether GM food should be labeled and the status of gene edited organisms.
Taking a less broad view it can encompass every organism that has had its genes altered by humans, which would include all crops and livestock.