In the TME, tumor-associated fibroblasts (TAFs), macrophages (TAMs) and mesenchymal stem cells secrete interleukin 6 (IL-6), interleukin 8 (IL-8), and chemokine (C-X-C motif) ligand 7 (CXCL7), stimulating the self-renewal of CSCs (3). The gene discussed is PPBP; the disease is neoplasm.