CCL8 and esophageal squamous cell carcinoma: To illustrate the mechanisms involved, CAFs were exposed to different CM from imperatorin‐treated or untreated ESCC cells, respectively, and compared by quantitative real‐time polymerase chain reaction (qRT‐PCR) for expression levels of a series of immune related cytokines such as vascular endothelial growth factor (VEGF), interleukin‐6 (IL‐6), fibroblasts‐secreted C‐C motif chemokine ligand 8 (CCL8).