Abstract: The Deep Underground Neutrino Experiment (DUNE) will be the leading next-generation particle project in the US.  It aims to measure CP violation in the neutrino sector and determine the mass ordering of neutrinos.  These measurements are straightforward conceptually but challenging practically.  One outstanding issue is the modeling of GeV neutrino-nucleus interaction.  With a lack of a proper theoretical framework, it is not only difficult to simulate neutrino events in the detector accurately but also difficult to assess its impact on the physics measurements.  I will discuss our attempts at understanding how cross-section uncertainties impact oscillation measurements and new physics searches.