RE: news.... and commentary for you to enjoy! DrJ "what if the test were longer than 21 days?"
And that is also a point that applies to the Spetember tests, these experiments are not "open-ended" but have to have an end-point so that the animals do not suffer distress (part of the rules, distress presumably because of the size of the tumours in the untreated animals?, and when they have to be killed the same goes for the treated animals).
Assuming this reasoning applies to this test, it would be nice if longer experiments were run and/or that the NR made point that there may (or may not) be further improvements if run longer, or at least that the experiment length (actually 35 days I think) was not (I assume) "the best expected result" duration.