M2 macrophages function in the clearance of pathogens, anti-inflammatory response, tissue repair, and tumor progression through producing inflammation regulators and tissue-proliferation activators, such as interleukin-10 (IL-10), peroxisome proliferator-activated receptor gamma (PPARγ), transforming growth factor-beta (TGF-β), and tissue inhibitor of metalloproteinases-1 (TIMP-1) [74,75]. This evidence concerns the gene TIMP1 and neoplasm.