Researches have indicated that Treg cells exert an essential role in the microenvironment, prognosis as well as response to chemotherapy in various tumors (53), and enhanced infiltration density of FoxP3 regulatory T cells is closely linked to poor prognosis in a number of tumors, for instance melanoma, lung cancer, cervical cancer, gastric cancer and liver cancer (54). Here, FOXP3 is linked to melanoma.