This isn't the first time that gene editing has been used to treat a human patient, nor the first time that it's been used against cancer cells. Late last year, we told you about doctors in Britain that used a different gene editing procedure -- TALEN -- to create modified T-cells. These cells were then implanted in a one-year-old child with a terminal case of acute lymphoblastic leukemia. By contrast, UPenn will be using CRISPR-Cas9, a different process which has been tested using human DNA in China, to do the same job.

The committee will only rubber-stamp the experiment if it's certain that researchers are giving their work the proper level of respect. As Dr. Carrie Wolinetz, a director at the National Institutes of Health, explains, officials will be looking to ensure the procedure "reflects well-established scientific and ethical principles." One key concern is that the process will shut down a component of our body's own immune response, much like an immunosuppressant drug. Should the team make a mistake, however, the consequences could pose a new set of risks for those undergoing treatment. But, since we're at the bleeding edge of medicine, it's hard to tell how far-reaching the consequences are.