CD8A and metastatic melanoma: Correlation analysis based on a model targeting six immune cells in patients with metastatic melanoma in TCGA (Model 1) showed that the risk score of the model correlated with the expression of macrophages (Spearman’s coefficient = −0.43, p < 0.01) and CD8+ T cells (Spearman’s coefficient = −0.46, p < 0.01) (Figure 8A).