Whoa! Thats some stuff that's over my head. It looks like we have a few scientists in here.

When at first you don't succeed, try try again. Many new discoveries come from failure. It will be interesting to find out what comes next.

That's a bummer, of course. I'd have to read the whole paper to make conclusions, of course. From the abstract, however, it seems that all they have to do, is just use a different source for Cas9. MAYBE they could use an alternative of Cas9 from a patient's own stem cells, or relative to avoid immune response as much as possible