Marije Niemeijer is assistant professor at the Cellular systems and Drug Safety division of the Leiden Academic Centre for Drug Research (LACDR) at Leiden University. She received her Masters degree cum laude in Bio-pharmaceutical Sciences with the specialization Toxicology at Leiden University. Thereafter, she did her PhD at the department of Toxicology of LACDR at Leiden University. Here, she studied the regulation and inter-individual variability of stress response signalling upon chemical exposure by combining siRNA screening, high-content imaging and transcriptomic approaches. As a post-doctoral researcher, she focused on the application of 3D liver models for toxicity testing within the Horizon2020 EU-ToxRisk and PATROLS project. Now as assistant professor, she aims to dissect molecular mechanisms of drug action in both the context of drug efficacy as well as toxicity using advanced in vitro test systems that are fit for this purpose. Through omics approaches, affected genes or networks for different areas within the chemical space or for specific pathologies can be identified and used as reporter genes. To further refine chemical risk assessment, she aims to characterize the inter-individual variability in the activation of these critical gene networks upon chemical exposure.