What is Gene Transfer?

In this blog, I define gene transfer as the use of genetic materials or genetically modified organisms for therapeutic or research purposes.  This is a much broader definition than typical.  For instance, the American Society of Gene Therapy defines gene therapy as "...an approach to treating disease by either modifying the expressions of an individual's genes or correction of abnormal genes."  My definition would include gene-marking protocols (whereby a patient's cells are genetically modified not for therapeutic purposes, but instead so that researchers can track their growth or location in the body).  My definition also includes the administration of genetically modified organisms-- like genetically modified gut flora—for therapeutic purposes.  My definition also includes vaccines made by genetically modifying viruses; several of these are presently being tested against cancer and HIV.