For example, it was shown that the recruitment of Tregs in melanomas was in fact dependent on CD8+ T cell, which occurred after the CD8+ T cell infiltration instead of preceding it [20]; furthermore, the upregulation of PD-L1 on tumor cells is induced by CD8+ T cells in an interferon (IFN)-γ-dependent manner [20, 21]. This evidence concerns the gene CD8A and melanoma.