Treg cells were recruited into the tumor microenvironment with chemokines (such as CCL-28-CCR10) secreted by tumor cells and innate immune cells and thereby can proliferate in situ by using cytokines (such as IL-10 and TGF-β) in the tumor microenvironment, thus playing a role in the formation of tumor microenvironment [35, 36]. This evidence concerns the gene CCL28 and neoplasm.