Much of the human genome consists of interspersed repetitive DNA sequences. Their structure closely resembles that of retroviruses , carrying internal sequences with homology to gag, pol, and sometimes env open reading frames flanked by long terminal repeats. Similar sequences occur in all organisms, from yeast to vertebrates. Al-Khayat HA, et al. To date this is the only known instance of insertional mutagenesis of the human genome caused by this type of element, but other examples look certain to be discovered in future.
Retroviruses are under active development as vectors for gene therapy .
Howard Temin's Scientific Legacy Haren, L. et al. Tang, H. et al. Lentivirus Replication and Regulation.