Here are a couple you might try:

Gene therapy tutorial. The Molecular Medicine in Action series
includes a tutorial on gene therapy.
http://www.iupui.edu/~wellsctr/MMIA/htm/animations.htm.
A useful introduction to both techniques and issues.

Gene therapy database. This site, from the US National Institutes of
Health and cooperating agencies, gives information on
US gene therapy trials. It includes the report of adverse events.
http://www.gemcris.od.nih.gov.

bob

thank you very much Bob..
Bye
Cordially Fabio