The NCI-PID 2.0 Knowledge Graph (ncipidkg) is an RDF representation of the National Cancer Institute Pathway Interaction Database networks, a curated resource describing human molecular signaling, regulatory events, and cellular processes with strong relevance to cancer biology. It exposes pathway knowledge as interoperable triples centered on proteins, molecular interactions, and regulatory relationships. The attached entity model shows that ncipidkg uses standard RDF and VoID structures for statements and dataset statistics, while representing biological predicates such as regulates, molecularly interacts with, directly regulates, directly positively regulates, and directly negatively regulates. Reified RDF statements carry edge-level metadata, including evidence counts, evidence URLs, and biological process or post-translational-modification types, often linked to Gene Ontology terms. By converting NCI-PID 2.0 networks into a queryable knowledge graph enriched with INDRA/NCI-PID evidence metadata, ncipidkg supports pathway exploration, provenance-aware analysis, and integration with broader biomedical open knowledge networks through SPARQL and linked-data access.
