https://www.nature.com/articles/s41467-019-12808-z
Authors. Kulp, S. A. & Strauss, B. H
Venue. Nature Communications
How the Institute flags it
established 5 times frontier 1 time
This source carries more than one flag across the corpus. That is not an inconsistency to resolve: the same work can be established evidence for one claim and frontier evidence for another, and the flag belongs to the use rather than to the source.