Henk-Jan Guchelaar is a hospital pharmacist and clinical pharmacologist.  Since 2003, he is employed as professor of clinical pharmacy and chair of the department of Clinical Pharmacy & Toxicology at Leiden University Medical Center. Since October 2008, he is also appointed professor of Clinical Pharmacy at the Faculty of Science, Leiden Academic Center for Drug Research, University Leiden and chair of the Leiden University focus area ‘Translational Drug Discovery and Development’. He is program leader of the research program ‘Personalised Therapeutics’  investigating interindividual variability of drug response with an emphasis on pharmacogenomics. He is (co-)author of more than 575 (Web of Science indexed) articles (Pubmed: 400) in international peer reviewed scientific journals. Guchelaar is coordinator of the EU funded Horizon 2020 project Ubiquitous Pharmacogenomics (www.upgx.eu) aimed at implementing pre-emptive pharmacogenomic testing in the EU. Since 2017, he is member of Council for Medical Sciences of the Royal Dutch Academy of Science and since 2020 member of the Academia Europea.