Suppose you are developing a CRISPR/Cas9 based therapy to treat inherited sickle cell disease which is caused by a mutation of a single base in the DNA sequence of the β-globin gene. You harvested stem cells from a patient with sickle cell disease and used CRISPR/Cas9 to correct the mutation in these cells. What is the next step in the development of this therapy?
1) Inject the corrected stem cells back into the patient
2) Administer a drug to activate the corrected gene in the stem cells
3) Perform clinical trials to test the safety and efficacy of the therapy
4) Develop a method to deliver the corrected gene to all cells in the patient's body