In line with a proposed function of gastric mucosal cell in regulating T cell–mediated immune responses, we observed up-regulated expression of cell surface molecules including Cd44, Lys6a (Sca1), Lys6d, Bst2, histocompatibility 2, Q region locus 6 (H2-Q6, the mouse orthologue of MHC-1E), and 7 (H2-Q7) and histocompatibility 2, T region locus 10 (H2-T10) in Yap1-depleted gastric tumor cells. This evidence concerns the gene BST2 and gastric neoplasm.