Nearly 60% of patients undergoing cancer treatment are estimated to have had at least one potential drug-drug interaction; for patients receiving oral anticancer therapy, up to 50% have been reported to experience a potential drug-drug interaction, with 16% experiencing a major event. Drug-drug interactions are therefore a significant issue for cancer patients and the health care professionals who treat them. Combining the internationally recognised drug-drug interactions expertise of the University of Liverpool (UK) with the clinical pharmacology in oncology and haemotology expertise of Radboud University, Nijmegen (the Netherlands), this site was established in 2017 in response to the need for improved management of DDIs with anti-cancer agents.