GZMB and melanoma: In the group of all malignant cases and primary melanomas only, a GrB/CD8 cell number ratio of <0.1 was associated with a better RFS (p-values < 0.001 and 0.019, respectively) and DSS (p-values 0.024 and 0.030, respectively), and was an independent positive prognostic factor for RFS in primary melanomas when Breslow’s depth was taken as a covariate in a multivariate analysis of survival (p = 0.012, HR: 0.195, 95% CI: 0.54–0.699) (Figure 3C).