Which of the following is a site of ex vivo gene therapy?

A) bone marrow
B) muscle
C) blood
D) lungs
E) brain

Ex vivo gene therapy involves removing cells from the body, genetically modifying them in a laboratory setting, and then reintroducing them back into the body. Bone marrow cells are commonly used in ex vivo gene therapy for disorders such as inherited blood disorders and certain types of cancers. Muscle, blood, lungs, and brain are not typically sites for ex vivo gene therapy.