Updated project metadata. Gastric cancer ranks the fifth most common malignancy and the third leading cause of cancer related death worldwide. Classical chemotherapy is still the standard treatment in advanced stages, with only two targeted therapies currently in clinical use. Several targeted trials have failed, likely due to missing relevant biomarkers that predict response. Patient derived cancer organoids (PDOs) constitute a three dimensional cell culture system showing self renewal, self organization and regularly unlimited proliferation while faithfully recapitulating many aspects of the tumor they are derived from. Nevertheless, the complex individual mutational landscape hampers the use of PDOs for basic and translational research. We therefore characterized three murine tumor organoid models with defined mutational patterns altering specific oncogenic pathways: a RAS activated (KrasG12D, Tp53R172H), a WNT activated (Apcfl/fl, Tp53R172H) and a diffuse (Cdh1fl/fl, Apcfl/fl) tumor model. The models were analyzed phenotypically, a proteome signature was established and a drug screen performed. The models were morphologically diverse, were characterized by individual protein expression signatures and showed differential drug sensitivities. The developed organoid models allow functional assays as well as pathway specific drug interference testing in a genetically defined setting.