Creation of stable recombinant retrovirus

[Overstressed]

While googling EBV, treatment and episome disruption, I came across this article:

http://www.stanford.edu/group/nolan/retroviral_systems/phx_episomals.html

It looks like they're using EBV vectors to create retroviruses, for gene therapy. It's complicated, but what are the consequences ?

Best regards,
OS.