Matt's research in gastrointestinal is focused on optimising the use of chemotherapy and other drug therapies for patients with colorectal and oesophagogastric cancer. He has designed and led a large number of clinical trials including small-scale pilots to optimise drug dosing, medium-scale trials to establish efficacy and large national (phase III) trials to change clinical practice. He was one of the first to establish the practice of routinely asking all patients participating in trials to donate a tumour and blood samples so that molecular characteristics of the tumour could be established which correlate with the drug efficacy or toxicity, so establishing "predictive biomarkers" to guide the optimum selection of treatment for future patients. In order to do this, he has worked in close partnership with pathologists and other laboratory scientists in Leeds and elsewhere.