CEDAR: A comprehensive database of curated cancer epitopes and receptors

The identification of immunogenic cancer epitopes, including patient-specific neoepitopes and shared tumor-associated antigens (TAAs), is a critical foundation for advancing effective cancer immunotherapies. To provide the community with a centralized data source for this research, the Cancer Epitope Database and Analysis Resource (CEDAR, cedar.iedb.org) offers the most extensive and actively updated collection of experimentally validated cancer epitope and receptor data. Currently, CEDAR hosts data from 6,242 publications, encompassing 152,636 T Cell Assays, 143,715 B Cell Assays, and 4,394,087 MHC Ligand Assays, covering 666 distinct restricting MHC alleles. CEDAR's comprehensive catalog includes neoepitopes, oncoviral epitopes, and TAAs, storing both positive and negative immune responses across human, mouse, and other species. The central element of the database is the experimental data validating these tumor molecule interactions; assay information is meticulously reported, including the specific assay types (e.g., ELISpot, tetramer staining, mass spectrometry) used to confirm T cell, B cell, and MHC binding/presentation. Furthermore, the database stores T and B cell receptors known to specifically recognize these epitopes. The strength of the CEDAR lies in its rigorous and transparent curation process. All entries are curated by PhD-level scientists following a publicly available curation manual that outlines specific, consistently applied rules for data extraction, validation, and annotation. Curators use extensively validated workflows that combine automated text-mining with detailed manual review to ensure completeness and accuracy. Data is annotated in a highly structured way using community-supported ontologies, such as Uniprot, the Disease Ontology, and The Ontology for Biomedical Investigations (OBI), among others. This high degree of standardization ensures data accuracy, maximizes interoperability, and enables users to perform highly granular queries, filtering by species, MHC molecules, cancer pathology, antigen type, and specific source antigens. As an integral and freely accessible companion site to the Immune Epitope Database (IEDB), CEDAR serves as a critical foundation for basic and translational immuno-oncology research. It provides the high-quality, trusted experimental data necessary for validating predictive models, designing targeted therapeutics, and exploring the landscape of tumor immunity.