These results imply an correlation between melatonin and HPFs, but whether melatonin reduces the secretion of potent oncogenic molecules by CAFs, such as TGF-β [161] and hepatocyte growth factor (HGF) [162], or inhibits other tumor microenvironment members, such as immune inflammatory cells and endothelial cells [163], should be investigated. The gene discussed is HGF; the disease is neoplasm.