Dennis studied molecular biomedicine at the University of Bonn and did his PhD in genetics at the Department of Translational Genomics lead by Professor Roman Thomas at the University of Cologne in 2015. During his PhD he worked on the characterization of new oncogenes and treatment options for lung cancer. For his first postdoc he joined the laboratory of Martin Sos and started investigating new treatment strategies for RET-rearranged tumors as well as the characterization of new structural variants of the MET receptor. At the end of 2017 Dennis joined the Tuveson laboratory at Cold Spring Harbor working on pancreatic cancer using the human organoid platform. Dennis investigates new treatment strategies and the translation of human organoid research to the clinics to further improve precision medicine approaches in pancreatic cancer.