Thus, the increased frequencies of IFNγ-producing Tregs or CD4 Teffs, and granzyme Bhigh CD8 Teffs in TILs by anti-PD-1 and anti-CD80 treatment may all have contributed to the melanoma regression, suggesting a potential combination therapy for melanoma with PD-1 and CD80 Abs. This evidence concerns the gene CD4 and melanoma.