PTGER4 and neoplasm: In the early stage of CRC carcinogenesis, colorectal CSCs remodel the immune microenvironment, undergo immune escape and drive their own self-propagation Exploiting DNA label retention, single-cell RNA sequencing, coculturing, cell depletion assays, and lineage tracing, He et al. revealed that intestinal CSCs remodel the tumor microenvironment (TME); for example, they remodel tumor-associated monocytes and macrophages (TAMMs), which in turn promote CSCs through the PGE2-EP4 pathway.