CDH1 and infection: Gastric organoid infection with a control adenovirus (Ad Fc) encoding an immunoglobulin Fc fragment [43] resulted in gastric organoids with wild-type Cdh1 and Tp53, while adenovirus Cre-green fluorescent protein (Ad Cre-GFP) induced deletion of the floxed Cdh1 and Trp53 alleles, with Cdh1 and Trp53 loss confirmed by immunofluorescence (Figure 5a and Additional file 1: Figure S2), accurately modeling the Cdh1 and Trp53 loss common to both the primary and metastatic tumors.