Or read about that gene therapy trial where some kid died just like that.

Welcome to Crohn's Disease.

No, really, that's pretty much how Crohn's works, as far as they've got it figured out (at least, as of the last time I spoke with my specialist): the GI tract has a sort of second immune system, and that immune system goes nuts and attacks the GI tract thinking it's defending it from an outside attacker. I certainly wouldn't wish that on anybody else, in any form.

On the other hand, imminent death from cancer...

I'll still chalk this up as an amazing medical breakthrough, but seriously keep my fingers crossed that this doesn't become a regular thing that happens due to this treatment.

See also: rheumatoid arthritis, another barely understood autoimmune disease where the immune system attacks the body's own synovial fluid, causing pain in the joints even without exertion. Hell, in my mom's case, it was even attacking her in places that didn't HAVE joints (synovial fluid is present damned near everywhere in the body, as it acts as a cushion not only between bones but organs as well). The most effective medication in her treatment regimen was an immunosupressant which is normally prescribed for chemo patients.

So yeah, maybe they can make this work, but I've got plenty of reason to doubt.

all antibody based medications, almost all of which have a "generic" name ending with "ab" to stand for "antibody," have the cross shape you see there. The difference between all of these drugs are in the makeup of the different binding regions.

Hallelujah! ALL the medicine looks like crosses!