For a drug to work in one race and then be completely useless outside it
The funny thing is, that is completely untrue in this situation
Maybe you didn't read the article.
A lot of our drugs even work on monkeys, so just because you get 10% effectiveness or something with whites is irrelevant.
Part of the problem is probably that many posters engage in discussions for which they are not factually prepared (i.e. in the area of biology). Anyone with even a rudimentary education in the field, for instance, would recognize how significant biological differences must be for a drug to work in one subgroup and not another (many drugs work across species lines-- look how often rats are valuable in researching drugs).
So, needless to say, something like this is definitive proof racial differences are more than "skin deep," since skin is unrelated to general biochemistry. Granted, many people presumably accept that hypothesis already-- but far, far from all. Many on this site do not, in the face of unarguable fact.