PubMed / MEDLINE

PubMed is operated by the U.S. National Library of Medicine at the NIH and has been the de facto front door to the biomedical literature since 1996. It indexes more than 38 million references spanning medicine, nursing, dentistry, veterinary medicine, public health and the life sciences, drawing on the MEDLINE core (about 5,200 peer-reviewed journals selected by the NLM Literature Selection Technical Review Committee) plus PubMed Central and a selection of bibliographic-but-not-MEDLINE records.

MEDLINE records are indexed with Medical Subject Headings (MeSH), the controlled vocabulary that lets clinicians and reviewers run reproducible, sensitive queries — the kind systematic reviews require. The free public interface includes filters for publication type, study design, age groups, species and date ranges, and an E-utilities API for programmatic access.

For disease researchers, PubMed is rarely the end of the search, but almost always the beginning: it surfaces the primary literature that the curated knowledge bases (OMIM, ClinVar, DisGeNET, Open Targets, and most others in this registry) cite as evidence.