CD8A and melanoma: Association of higher levels of PD-1+ EVs from CD8+ T cells with poor response.Association of higher levels of PD-L1+ EVs from melanoma cells with poor response. AUC=0.86 for the combination of (PD-1 EVs from CD8+ T cells and PD-L1+EVs from melanoma cells) showing a strong predictive value for poor prognosis.