Immunohistochemical images of CD31, a marker of mature blood vessels, showed that CD31 expression in tumor xenografts was higher in S2-013-organoid mice 8 weeks after implantation than in the S2-013-conventional model (Fig. 2E for the S2-013-conventional model, 2F for the S2-013-organoid mice). This evidence concerns the gene PECAM1 and neoplasm.