Gene therapy is not the replacement of genes and is much more than sim
ple gene augmentation, Gene therapy is better defined as the genetic a
lteration of cells, and for that reason encompasses an enormous scope
of therapeutics that is rapidly growing, Although its promises are gre
at, related toxicities pose a potential problem. Thus, as gene therapy
promises to become another set of pharmaceutical agents, gene therapy
monitoring may someday become as common as therapeutic drug monitorin
g is today.