Presently,somatic Cell Gene Therapy for ADA-SCID Presents Challenges

Multiple Choice

Presently,somatic cell gene therapy for ADA-SCID presents challenges.What are those challenges?

A) The therapy is too expensive
B) The therapy is transient an the gene promoters are silenced by the host quickly
C) The functional gene copy is lost during introduction
D) The lifespan of red blood cells is short
E) None of these