CXCL12 and colorectal carcinoma: Similarly, a coculture system with monocytes, CD8 + T cells, and patients derived tumor organoids was used to study the relationship between CD8 + T cells and tumor cells, but contrary trend between CD8 + T cells and tumor associated macrophages has been observed that is involved in CXCR4/CXCL12 pathway [273], and colonic organoid is used to explore the resistance to immune check blockage, which is accompanied by a peritoneal metastases [274], and organoid is also used to epigenetically analyzed the MHC-II which is repressed in CRC [275].