It was shown that melanoma growth and progression is correlated with the presence of Treg cells within the tumor and that their recruitment by cancer cells helps them avoid the immune response, mainly through secreted cytokines and chemokines with immunosuppressive activity, such as tumor growth factor β (TGF-β) and interleukins (ILs): IL-10 and IL-35 [15,23,24]. This evidence concerns the gene IL10 and cancer.