Renier Adrianus Leonardus van der Hoorn was born in Leiden in 1971 and was fascinated by plant biology from early childhood. He studied chemistry at Leiden University and focused soon on plant molecular biology and biochemistry. After his graduation in 1996, he started his PhD in Molecular Phytopathology (Wageningen University, Prof. Dr. Pierre de Wit), where he worked on the tomato Cf resistance proteins. He continued working on Cf proteins in Wageningen as a postdoc, and started his own research program by introducing and applying activity-based protein profiling (ABPP) in plants. To further develop ABPP he joined the phosphoproteomics group of Dr. Scott Peck for one year (Sainsbury lab, John Innes Centre, Norwich, UK). He initiated the Plant Chemetics lab in 2005 at the Max Planck Institutes of Cologne and Dortmund as part of the Chemical Genomics Centre of the Max Planck Society. His research group operated independently from the departments at the Max Planck Institutes while he trained twelve MSc students, nine PhD students, eleven postdocs and hosted over 30 visiting scientists. Since October 2013 he is Associate Professor and since 2017 Full Professor at the Department of Plant Sciences of the University of Oxford, and Tutor in Plant Sciences at Somerville College. Since 2022 he is an RS4 Professor at the Department of Biology and a Senior Research Fellow at Somerville College. His research focusses on improving transient protein expression in plants and using chemical proteomics and structural modeling to uncover novel host manipulation mechanisms employed by microbes when colonizing the apoplast.