Which of the Following Statements About Gene Therapy in Humans

Which of the following statements about gene therapy in humans is FALSE?

A) A major problem with treatment can be an adverse immune response.
B) The vector may insert into a cancer-causing gene.
C) Genes have been inserted into reproductive tissue so that the children of the patient will also be helped.
D) Gene therapy has been used successfully to treat several children with X-linked adrenoleukodystrophy, a fatal disorder of the central nervous system.
E) Viruses are often used as vectors in gene therapy.