Gene targeting (also, replacement strategy based on homologous recombination) is a
genetic technique that uses
homologous recombination to change an
endogenous gene. The method can be used to delete a gene, remove
exons, add a gene, and introduce
point mutations. Gene targeting can be permanent or conditional. Conditions can be a specific time during
development / life of the organism or limitation to a specific
tissue, for example. Gene targeting requires the creation of a specific
vector for each gene of interest. However, it can be used for any gene, regardless of transcriptional activity or gene size.