Ann: Final Preclinical Asthma Study Confirms Efficacy, page-41

Thanks @pfeifer1982.

page 5 - "Subepithelial collagen deposition" and "Total lung collagen concentration (fibrosis)"
are the most relevant sections, but I've read the whole paper reasonably closely, I think.

I see why they feel they can say "abrogates" and "reverses" despite that they never measure fibrosis before and after in the same mouse or mice.

Because the MSC treatments in the experimental group occurs after both the control and experimental groups are subjected to 9 weeks of disease induction, and because the intra-nasal (IN) treated MSC group is no worse (for fibrosis markers) than a control group of mice which is not subjected to 9 weeks of disease induction (but otherwise treated the same), they conclude harm occurred (although it was not directly observed - no tissue samples taken to prove harm in the later cured mice) and was reversed or abrogated subsequently (as a result of the MSC IN treatments) so that the tissue samples for control and treatment group were the same.

Crucial to accepting their conclusion that abrogation or reversal (of fibrosis) has occurred is that there is no other confounding variables apparent or explanations for the observed result.

Their conclusion (of abrogation or reversal of fibrosis) relies on correlational data. Their method doesn't demonstrate an unambiguous causal link where mice with evident fibrosis at one time are shown to have less of it later after MSC treatments. Rather we have to believe or assume that one set of eight mice is pretty much the same as another so if one set of eight mice got fibrosis to a certain extent then the other also would have to a very similar extent despite that we don't get to see it.