Dr. Jacco de Haan is an internist and medical oncologist at the Department of Medical Oncology at the UMCG. He is involved in care, teaching, and research. His expertise spans oesophageal and gastric cancers and sarcomas. His research focus is on the role of the gut wall and the gut microbiome in the efficacy and toxicity of anticancer medication. A second important research topic concerns the presence and impact of taste and smell disturbances caused by anticancer therapies. He has formed a national expertise group consisting of physicians, researchers, dietitians, nurses, gastronomic chefs and patient advocates to address this problem.  In 2023, he received a KWF grant to establish better treatment options for patients with taste and smell alterations by performing multicenter intervention studies.