Identifying evidence implicating targets with diseases or phenotypes constitutes one of the pivotal challenges of the Open Targets Platform (Figure 1C). We currently maintain 20 different data sources capturing knowledge on target–disease relationships covering the following categories: genetic associations (for germline variation on common and rare diseases), somatic mutations, drugs, pathways and systems biology, RNA expression, text mining and animal models (Figure 3). All 10 154 924 pieces of evidence are mapped and curated using a reference target entity identifier (Ensembl gene) and disease or phenotype identifier (experimental factor ontology, EFO) (17).
