For example, chemokines generated by TCSCs, such as CCL2, CCL15, and CSF 1, can attract macrophages to the tumor ecotone (11), and more importantly, macrophages entering the ecotone of TCSCs can be polarized to M2-like TAMs by IL4, IL13, and TGF-ß to promote the formation of a tumor-immunosuppressive microenvironment (81, 82). Here, CCL2 is linked to neoplasm.