Not all genetically engineered organisms cause genetic pollution. Genetic engineering has a variety of uses and is specifically defined as a direct manipulation of the genome of an organism. Genetic pollution can occur in response to the introduction of a species that is not native to a particular environment, and genetically engineered organisms are examples of individuals that could cause genetic pollution following introduction. Due to these risks, studies have been done in order to assess the risks of genetic pollution associated with organisms that have been genetically engineered: