PMC has updated the Associated Data box to display unique identifiers assigned to
supplemental material files by the publisher when available (e.g., DOI; see PMC6351104). In cases
where the publisher has not assigned a unique ID to a supplemental file, NLM will generate
and display a Globally Unique Identifier (GUID; see PMC6351564). This update
aims to support the reporting of datasets as well as the citation and discovery of this
Publishers that are interested in supplying unique IDs for supplemental material files with
their PMC submissions should visit the Tagging Guidelines.