The ROBOKOP v1.0 knowledge graph system for exploring relationships between biomedical entities

ROBOKOP (Reasoning Over Biomedical Objects linked in Knowledge Oriented Pathways) is an open-source, modular, biomedical, knowledge graph (KG)-based system comprised of several key components: the ROBOKOP KG; a user interface (UI); and a variety of supporting resources, including tools and services to support deep exploration of the ROBOKOP KG and each of its underlying knowledge sources. A custom software pipeline termed Operational Routine for the Ingest and Output of Networks (ORION) standardizes, integrates, and harmonizes ROBOKOP's knowledge sources as interoperable KGs by leveraging the community-developed Biolink Model's universal KG schema and upper-level biomedical ontology. A ROBOKOP Graphs interface exposes the ROBOKOP KG and the other interoperable KGs, thus supporting access independent of the UI. All components of ROBOKOP are publicly accessible. Herein, we describe the v1.0 major release of ROBOKOP and highlight its features and functionalities in several application use cases, including a validation use case on asthma gene targets and two user-provided exploratory use cases on cardiotoxicity related to exposure to brominated flame retardants and diabetes mellitus related to exposure to agricultural pesticides.