Genetic engineering has the potential to correct
human genetic disorders. In gene therapy, a
defective gene is replaced by using a virus to
insert a normal gene into the cells of an
individual. This treatment will be most
successful if the virus is inserted into cells that
(1) lack a nucleus
(2) are recycled after death, rather than
removed from the body
(3) carry out one specific function, rather than
multiple functions
(4) continue to divide during the life of the
patient