STAT3 and neoplasm: Like MDSCs, tumor associated macrophages (TAMs) also can play substantial roles in preventing anti-tumor responses and macrophages co-cultured with prostate epithelial cells may be induced to this phenotype, producing the chemokine CCL4 in a STAT3 dependent manner which induces spontaneous prostate tumorogenesis in normal prostate cells associated with the downregulation of p53/PTEN as well as the induction of EMT [73,121].