CD274 and gastric neoplasm: Chakrabarti et al. co‐cultured cytotoxic T lymphocytes (CTLs) with bone marrow‐derived dendritic cells activated by tumor antigens released by mouse gastric tumor organoids, and found stimulated CTL had a killing effect on gastric tumor organoids in the presence of PD‐L1 antibodies, demonstrating that the model of co‐culture a variety of immune cells with organoids to mimic the tumor immune microenvironment can effectively study the interaction between tumor cells and immune cells, as well as between immune cells.72