2020 marks the 40th anniversary of the first GRC on Proteolytic Enzymes and Their Inhibitors. Although the title of the conference has not changed, the focus of research has shifted from structural studies and basic biochemical mechanisms to investigations into the regulation of protease activity in health and disease. Since proteins are the workhorses of biology, it is unsurprising that processing of proteins by proteolysis is a ubiquitous regulatory mechanism. The activity of proteases is in turn regulated by proteolytic processing, and also by cofactors that modulate specificity, and, of course, by inhibitors. Proteases play key roles in cellular processes as diverse as cell-cycle control, differentiation, apoptosis/pyroptosis, signalling, protein recycling/degradation, trafficking, protein maturation and cell motility. On an organism level proteases control physiological processes such as inflammation, blood coagulation, hormone generation, angiogenesis, tissue remodelling, wound repair and reproduction. The theme of the 2020 meeting is the regulation of proteolytic processes in health and disease, and the application of insights towards improved diagnosis and treatment of the many diseases involving protease dysregulation. As in previous years, attendees will represent a wide range of biology and scientific disciplines, with a healthy balance of participation from academia and industry and from established investigators, postdocs and students. In the "Spirit of the Gordon Conference", every attendee is expected to present unpublished data in either a poster or an oral presentation, and to engage in constructive and lively scientific discussion. We are delighted to yet again have a GRS preceding this meeting, providing young investigators a chance to share their data in a slightly less intimidating setting. However, the two talks voted most outstanding by the GRS attendees will be presented at the main meeting in the Late-Breaking Topics session, along with other presentations selected from submitted abstracts.