The Adverse Outcome Pathway (AOP) Pathways

This Adverse Outcome Pathway (AOP) Community is created to highlight the molecular basis of AOPs, or events in, AOPS. In general, AOPs start with a Molecular Initiating Event (MIE) caused by a stressor, followed by Key Events (KEs), that lead to an Adverse Outcome (AO). These AOPs are intended specifically for regulatory decision making and are typically stored in the AOP Knowledge Base (AOPKB). Because AOPs are simplified explanations of biological effects after the effect of a stressor they are not useful to describe and understand the molecular basis of the AOPs and not suited to do data analysis. Such analysis is needed especially for in silico risk analysis intending to lower animal use in toxicology studies. This community page was created to present this previously missing molecular level of the AOPs and get more into detail on the biological processes involved in them. The development of these molecular AOPs is relevant for the European research projects on toxicology EU-ToxRisk, OpenRiskNet and VHP4Safety that also funded part of the work. This community page is also featured in the latest NAR Database Issue on WikiPathways.


Friederike Ehrhart , Marvin Martens , and Penny Nymark .

Community Pathways

Table Filters
This community helps to curate 18 pathways:


Martens M, et al. (2018) Introducing WikiPathways as a data-source to support Adverse Outcome Pathways for regulatory risk assessment of chemicals and nanomaterials. Front Genet.

How to Contribute

The list of pathways is not static and can be updated at any time. If you know of a pathway that should be added, please contact the administrator, Marvin Martens (marvin.martens[AT]


This project has received funding from the European Union’s Horizon 2020 research and innovation programme project EU-ToxRisk under grant agreement No. 681002, EINFRA-22-2016 programme project OpenRiskNet under grant agreement No. 731075 and VHP4Safety under NWA grant no. 1292.19.272.

Community Members

Friederike Ehrhart , Marvin Martens , and Penny Nymark .

Authors of Community Pathways

Friederike Ehrhart , Marvin Martens , Penny Nymark , Finterly Hu , Alex Pico , Eric Weitz , Zuzanna Lech , Martina Summer-Kutmon , Egon Willighagen , Chris Evelo , Alexandra Bosch , PhilipErnst , JJv Heijden , Jeroen Kearns , Chesley De Windt , MysticArchers , Linda Rieswijk , Kristina Hanspers , Jonathan Mélius , Laurent Winckers , Anwesha Bohler , Bart Smeets , Fernando Torres Andón , Denise Slenter , JPM van Rijn , Andra Waagmeester , Tim Verbruggen , Elisa Cirillo , and Celine Malyar .