What Is Life? 2nd Edition by Jay Phelan

Exercise 52

Which of the following is not a difficulty that medicine has encountered in its attempts to cure human diseases through gene therapy?
A) The transfer organism-usually a virus-may get into unintended cells and cause disease.
B) It is difficult to get the working gene into the specific cells where it is needed.
C) It is difficult to get the working gene into enough cells at the right rate to have a physiological effect.
D) For many diseases, a malfunctioning gene has not been identified.
E) All of the above are difficulties encountered in attempts to cure human diseases through gene therapy.