For instance, Kim et al. demonstrated that tumor-associated macrophages promote prostate cancer bone metastasis through the production of IL-6, which in turn recruits more macrophages to the tumor site that produce further TNF-α, leading to increased production of IL-6 by tumor cells.38 The role of tumor-associated macrophages in the progression of pancreatic cancer has been well documented.39 Accordingly, the biological importance and clinical relevance of the present findings warrant further in vivo evaluation. This evidence concerns the gene TNF and prostate cancer.