I don't quite understand, tbh.
It says
and
Which to me (granted, not really understanding much about the topic) seems to be saying that these are people who got this cancer in the first place because they had a genetic condition that caused this particular DNA-mutation, that led to cancer, but that this treatment works because it can target precisely the cells with that particular mutated DNA.
It doesn't seem, as far as I can understand it, that therefore it would target any cancer in anybody, it sounds as if it's targeted at the kind of cancer-causing cell anomaly that people with this genetic condition can get.
Or is the treatment, in principle, able to target _any_ kind of mutated cell (whatever we choose to pick as the target), not just the one that this genetic condition leads to (and that all cancers - presumably, by the nature of cancer - have some kind of mutated DNA that we can in theory target?)