WP 1 (Biological Domain) is dedicated to the collection of data on human (patho)physiology at the molecular and cellular level underlying the case studies. Data of interest to WP 1 includes mRNAs, proteins and metabolite sets relevant to the selected systemic repeated dose toxicity effects and their corresponding organ functions. The resulting physiological data feeds into the pipeline to be structured into physiological maps that will serve as the basis for the build of AOP networks and the development of a testing strategy.

Examples of databases that have been used as resources include handbooks, library and repository platforms, such as PubMed, WikiPathways and AOP Wiki, whereas in parallel, tissue-specific databases will be screened, including, but not limited to, the DrugMatrix, the Toxicogenomics Project-Genomics Assisted Toxicity Evaluation system (TG-GATEs), the LiverTox database, the Liver Toxicity Knowledge Base and the databases of the Critical Path Institute. Another source includes mechanistic information from recent European projects, such as SEURAT-1 and HeCaToS (UM).